diff --git a/README.md b/README.md
index c5fdf925..dbcea723 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,9 @@ Serverless plugin for zero-config Typescript support
 ## Install
 
 ```sh
-yarn add --dev serverless-plugin-typescript
+yarn add --dev serverless-plugin-typescript typescript
+# or
+npm install -D serverless-plugin-typescript typescript
 ```
 
 Add the following plugin to your `serverless.yml`:
@@ -38,6 +40,7 @@ The default `tsconfig.json` file used by the plugin looks like this:
     "preserveConstEnums": true,
     "strictNullChecks": true,
     "sourceMap": true,
+    "allowJs": true,
     "target": "es5",
     "outDir": ".build",
     "moduleResolution": "node",
diff --git a/example/package.json b/example/package.json
index 8c0c8e77..d4945b34 100644
--- a/example/package.json
+++ b/example/package.json
@@ -6,6 +6,6 @@
   "devDependencies": {
     "@types/lodash": "4.14.91",
     "@types/node": "^11.13.0",
-    "serverless-plugin-typescript": "1.1.5"
+    "serverless-plugin-typescript": "1.1.7"
   }
 }
diff --git a/example/yarn.lock b/example/yarn.lock
index 4b8e261a..6ea4949e 100644
--- a/example/yarn.lock
+++ b/example/yarn.lock
@@ -2,11 +2,54 @@
 # yarn lockfile v1
 
 
+"@mrmlnc/readdir-enhanced@^2.2.1":
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/@mrmlnc/readdir-enhanced/-/readdir-enhanced-2.2.1.tgz#524af240d1a360527b730475ecfa1344aa540dde"
+  dependencies:
+    call-me-maybe "^1.0.1"
+    glob-to-regexp "^0.3.0"
+
+"@nodelib/fs.stat@^1.1.2":
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/@nodelib/fs.stat/-/fs.stat-1.1.3.tgz#2b5a3ab3f918cca48a8c754c08168e3f03eba61b"
+
+"@types/events@*":
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/@types/events/-/events-3.0.0.tgz#2862f3f58a9a7f7c3e78d79f130dd4d71c25c2a7"
+
+"@types/glob@^7.1.1":
+  version "7.1.1"
+  resolved "https://registry.yarnpkg.com/@types/glob/-/glob-7.1.1.tgz#aa59a1c6e3fbc421e07ccd31a944c30eba521575"
+  dependencies:
+    "@types/events" "*"
+    "@types/minimatch" "*"
+    "@types/node" "*"
+
 "@types/lodash@4.14.91":
   version "4.14.91"
   resolved "https://registry.yarnpkg.com/@types/lodash/-/lodash-4.14.91.tgz#794611b28056d16b5436059c6d800b39d573cd3a"
 
-array-union@^1.0.1:
+"@types/minimatch@*":
+  version "3.0.3"
+  resolved "https://registry.yarnpkg.com/@types/minimatch/-/minimatch-3.0.3.tgz#3dca0e3f33b200fc7d1139c0cd96c1268cadfd9d"
+
+"@types/node@*", "@types/node@^11.13.0":
+  version "11.13.0"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-11.13.0.tgz#b0df8d6ef9b5001b2be3a94d909ce3c29a80f9e1"
+
+arr-diff@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/arr-diff/-/arr-diff-4.0.0.tgz#d6461074febfec71e7e15235761a329a5dc7c520"
+
+arr-flatten@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/arr-flatten/-/arr-flatten-1.1.0.tgz#36048bbff4e7b47e136644316c99669ea5ae91f1"
+
+arr-union@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/arr-union/-/arr-union-3.1.0.tgz#e39b09aea9def866a8f206e288af63919bae39c4"
+
+array-union@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/array-union/-/array-union-1.0.2.tgz#9a34410e4f4e3da23dea375be5be70f24778ec39"
   dependencies:
@@ -16,14 +59,34 @@ array-uniq@^1.0.1:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/array-uniq/-/array-uniq-1.0.3.tgz#af6ac877a25cc7f74e058894753858dfdb24fdb6"
 
-arrify@^1.0.1:
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/arrify/-/arrify-1.0.1.tgz#898508da2226f380df904728456849c1501a4b0d"
+array-unique@^0.3.2:
+  version "0.3.2"
+  resolved "https://registry.yarnpkg.com/array-unique/-/array-unique-0.3.2.tgz#a894b75d4bc4f6cd679ef3244a9fd8f46ae2d428"
+
+assign-symbols@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/assign-symbols/-/assign-symbols-1.0.0.tgz#59667f41fadd4f20ccbc2bb96b8d4f7f78ec0367"
+
+atob@^2.1.1:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/atob/-/atob-2.1.2.tgz#6d9517eb9e030d2436666651e86bd9f6f13533c9"
 
 balanced-match@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
 
+base@^0.11.1:
+  version "0.11.2"
+  resolved "https://registry.yarnpkg.com/base/-/base-0.11.2.tgz#7bde5ced145b6d551a90db87f83c558b4eb48a8f"
+  dependencies:
+    cache-base "^1.0.1"
+    class-utils "^0.3.5"
+    component-emitter "^1.2.1"
+    define-property "^1.0.0"
+    isobject "^3.0.1"
+    mixin-deep "^1.2.0"
+    pascalcase "^0.1.1"
+
 brace-expansion@^1.1.7:
   version "1.1.8"
   resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.8.tgz#c07b211c7c952ec1f8efd51a77ef0d1d3990a292"
@@ -31,20 +94,173 @@ brace-expansion@^1.1.7:
     balanced-match "^1.0.0"
     concat-map "0.0.1"
 
+braces@^2.3.1:
+  version "2.3.2"
+  resolved "https://registry.yarnpkg.com/braces/-/braces-2.3.2.tgz#5979fd3f14cd531565e5fa2df1abfff1dfaee729"
+  dependencies:
+    arr-flatten "^1.1.0"
+    array-unique "^0.3.2"
+    extend-shallow "^2.0.1"
+    fill-range "^4.0.0"
+    isobject "^3.0.1"
+    repeat-element "^1.1.2"
+    snapdragon "^0.8.1"
+    snapdragon-node "^2.0.1"
+    split-string "^3.0.2"
+    to-regex "^3.0.1"
+
+cache-base@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/cache-base/-/cache-base-1.0.1.tgz#0a7f46416831c8b662ee36fe4e7c59d76f666ab2"
+  dependencies:
+    collection-visit "^1.0.0"
+    component-emitter "^1.2.1"
+    get-value "^2.0.6"
+    has-value "^1.0.0"
+    isobject "^3.0.1"
+    set-value "^2.0.0"
+    to-object-path "^0.3.0"
+    union-value "^1.0.0"
+    unset-value "^1.0.0"
+
+call-me-maybe@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/call-me-maybe/-/call-me-maybe-1.0.1.tgz#26d208ea89e37b5cbde60250a15f031c16a4d66b"
+
+class-utils@^0.3.5:
+  version "0.3.6"
+  resolved "https://registry.yarnpkg.com/class-utils/-/class-utils-0.3.6.tgz#f93369ae8b9a7ce02fd41faad0ca83033190c463"
+  dependencies:
+    arr-union "^3.1.0"
+    define-property "^0.2.5"
+    isobject "^3.0.0"
+    static-extend "^0.1.1"
+
+collection-visit@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/collection-visit/-/collection-visit-1.0.0.tgz#4bc0373c164bc3291b4d368c829cf1a80a59dca0"
+  dependencies:
+    map-visit "^1.0.0"
+    object-visit "^1.0.0"
+
+component-emitter@^1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/component-emitter/-/component-emitter-1.2.1.tgz#137918d6d78283f7df7a6b7c5a63e140e69425e6"
+
 concat-map@0.0.1:
   version "0.0.1"
   resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
 
-dir-glob@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/dir-glob/-/dir-glob-2.0.0.tgz#0b205d2b6aef98238ca286598a8204d29d0a0034"
+copy-descriptor@^0.1.0:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/copy-descriptor/-/copy-descriptor-0.1.1.tgz#676f6eb3c39997c2ee1ac3a924fd6124748f578d"
+
+debug@^2.2.0, debug@^2.3.3:
+  version "2.6.9"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
+  dependencies:
+    ms "2.0.0"
+
+decode-uri-component@^0.2.0:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/decode-uri-component/-/decode-uri-component-0.2.0.tgz#eb3913333458775cb84cd1a1fae062106bb87545"
+
+define-property@^0.2.5:
+  version "0.2.5"
+  resolved "https://registry.yarnpkg.com/define-property/-/define-property-0.2.5.tgz#c35b1ef918ec3c990f9a5bc57be04aacec5c8116"
+  dependencies:
+    is-descriptor "^0.1.0"
+
+define-property@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/define-property/-/define-property-1.0.0.tgz#769ebaaf3f4a63aad3af9e8d304c9bbe79bfb0e6"
+  dependencies:
+    is-descriptor "^1.0.0"
+
+define-property@^2.0.2:
+  version "2.0.2"
+  resolved "https://registry.yarnpkg.com/define-property/-/define-property-2.0.2.tgz#d459689e8d654ba77e02a817f8710d702cb16e9d"
+  dependencies:
+    is-descriptor "^1.0.2"
+    isobject "^3.0.1"
+
+dir-glob@^2.2.2:
+  version "2.2.2"
+  resolved "https://registry.yarnpkg.com/dir-glob/-/dir-glob-2.2.2.tgz#fa09f0694153c8918b18ba0deafae94769fc50c4"
   dependencies:
-    arrify "^1.0.1"
     path-type "^3.0.0"
 
-fs-extra@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-5.0.0.tgz#414d0110cdd06705734d055652c5411260c31abd"
+expand-brackets@^2.1.4:
+  version "2.1.4"
+  resolved "https://registry.yarnpkg.com/expand-brackets/-/expand-brackets-2.1.4.tgz#b77735e315ce30f6b6eff0f83b04151a22449622"
+  dependencies:
+    debug "^2.3.3"
+    define-property "^0.2.5"
+    extend-shallow "^2.0.1"
+    posix-character-classes "^0.1.0"
+    regex-not "^1.0.0"
+    snapdragon "^0.8.1"
+    to-regex "^3.0.1"
+
+extend-shallow@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/extend-shallow/-/extend-shallow-2.0.1.tgz#51af7d614ad9a9f610ea1bafbb989d6b1c56890f"
+  dependencies:
+    is-extendable "^0.1.0"
+
+extend-shallow@^3.0.0, extend-shallow@^3.0.2:
+  version "3.0.2"
+  resolved "https://registry.yarnpkg.com/extend-shallow/-/extend-shallow-3.0.2.tgz#26a71aaf073b39fb2127172746131c2704028db8"
+  dependencies:
+    assign-symbols "^1.0.0"
+    is-extendable "^1.0.1"
+
+extglob@^2.0.4:
+  version "2.0.4"
+  resolved "https://registry.yarnpkg.com/extglob/-/extglob-2.0.4.tgz#ad00fe4dc612a9232e8718711dc5cb5ab0285543"
+  dependencies:
+    array-unique "^0.3.2"
+    define-property "^1.0.0"
+    expand-brackets "^2.1.4"
+    extend-shallow "^2.0.1"
+    fragment-cache "^0.2.1"
+    regex-not "^1.0.0"
+    snapdragon "^0.8.1"
+    to-regex "^3.0.1"
+
+fast-glob@^2.2.6:
+  version "2.2.6"
+  resolved "https://registry.yarnpkg.com/fast-glob/-/fast-glob-2.2.6.tgz#a5d5b697ec8deda468d85a74035290a025a95295"
+  dependencies:
+    "@mrmlnc/readdir-enhanced" "^2.2.1"
+    "@nodelib/fs.stat" "^1.1.2"
+    glob-parent "^3.1.0"
+    is-glob "^4.0.0"
+    merge2 "^1.2.3"
+    micromatch "^3.1.10"
+
+fill-range@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/fill-range/-/fill-range-4.0.0.tgz#d544811d428f98eb06a63dc402d2403c328c38f7"
+  dependencies:
+    extend-shallow "^2.0.1"
+    is-number "^3.0.0"
+    repeat-string "^1.6.1"
+    to-regex-range "^2.1.0"
+
+for-in@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/for-in/-/for-in-1.0.2.tgz#81068d295a8142ec0ac726c6e2200c30fb6d5e80"
+
+fragment-cache@^0.2.1:
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/fragment-cache/-/fragment-cache-0.2.1.tgz#4290fad27f13e89be7f33799c6bc5a0abfff0d19"
+  dependencies:
+    map-cache "^0.2.2"
+
+fs-extra@^7.0.1:
+  version "7.0.1"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-7.0.1.tgz#4f189c44aa123b895f722804f55ea23eadc348e9"
   dependencies:
     graceful-fs "^4.1.2"
     jsonfile "^4.0.0"
@@ -54,9 +270,24 @@ fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
 
-glob@^7.1.2:
-  version "7.1.2"
-  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.2.tgz#c19c9df9a028702d678612384a6552404c636d15"
+get-value@^2.0.3, get-value@^2.0.6:
+  version "2.0.6"
+  resolved "https://registry.yarnpkg.com/get-value/-/get-value-2.0.6.tgz#dc15ca1c672387ca76bd37ac0a395ba2042a2c28"
+
+glob-parent@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/glob-parent/-/glob-parent-3.1.0.tgz#9e6af6299d8d3bd2bd40430832bd113df906c5ae"
+  dependencies:
+    is-glob "^3.1.0"
+    path-dirname "^1.0.0"
+
+glob-to-regexp@^0.3.0:
+  version "0.3.0"
+  resolved "https://registry.yarnpkg.com/glob-to-regexp/-/glob-to-regexp-0.3.0.tgz#8c5a1494d2066c570cc3bfe4496175acc4d502ab"
+
+glob@^7.1.3:
+  version "7.1.3"
+  resolved "https://registry.yarnpkg.com/glob/-/glob-7.1.3.tgz#3960832d3f1574108342dafd3a67b332c0969df1"
   dependencies:
     fs.realpath "^1.0.0"
     inflight "^1.0.4"
@@ -65,24 +296,53 @@ glob@^7.1.2:
     once "^1.3.0"
     path-is-absolute "^1.0.0"
 
-globby@^7.0.0:
-  version "7.1.1"
-  resolved "https://registry.yarnpkg.com/globby/-/globby-7.1.1.tgz#fb2ccff9401f8600945dfada97440cca972b8680"
+globby@^9.2.0:
+  version "9.2.0"
+  resolved "https://registry.yarnpkg.com/globby/-/globby-9.2.0.tgz#fd029a706c703d29bdd170f4b6db3a3f7a7cb63d"
   dependencies:
-    array-union "^1.0.1"
-    dir-glob "^2.0.0"
-    glob "^7.1.2"
-    ignore "^3.3.5"
-    pify "^3.0.0"
-    slash "^1.0.0"
+    "@types/glob" "^7.1.1"
+    array-union "^1.0.2"
+    dir-glob "^2.2.2"
+    fast-glob "^2.2.6"
+    glob "^7.1.3"
+    ignore "^4.0.3"
+    pify "^4.0.1"
+    slash "^2.0.0"
 
 graceful-fs@^4.1.2, graceful-fs@^4.1.6:
   version "4.1.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.11.tgz#0e8bdfe4d1ddb8854d64e04ea7c00e2a026e5658"
 
-ignore@^3.3.5:
-  version "3.3.7"
-  resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.7.tgz#612289bfb3c220e186a58118618d5be8c1bab021"
+has-value@^0.3.1:
+  version "0.3.1"
+  resolved "https://registry.yarnpkg.com/has-value/-/has-value-0.3.1.tgz#7b1f58bada62ca827ec0a2078025654845995e1f"
+  dependencies:
+    get-value "^2.0.3"
+    has-values "^0.1.4"
+    isobject "^2.0.0"
+
+has-value@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/has-value/-/has-value-1.0.0.tgz#18b281da585b1c5c51def24c930ed29a0be6b177"
+  dependencies:
+    get-value "^2.0.6"
+    has-values "^1.0.0"
+    isobject "^3.0.0"
+
+has-values@^0.1.4:
+  version "0.1.4"
+  resolved "https://registry.yarnpkg.com/has-values/-/has-values-0.1.4.tgz#6d61de95d91dfca9b9a02089ad384bff8f62b771"
+
+has-values@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/has-values/-/has-values-1.0.0.tgz#95b0b63fec2146619a6fe57fe75628d5a39efe4f"
+  dependencies:
+    is-number "^3.0.0"
+    kind-of "^4.0.0"
+
+ignore@^4.0.3:
+  version "4.0.6"
+  resolved "https://registry.yarnpkg.com/ignore/-/ignore-4.0.6.tgz#750e3db5862087b4737ebac8207ffd1ef27b25fc"
 
 inflight@^1.0.4:
   version "1.0.6"
@@ -95,28 +355,239 @@ inherits@2:
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/inherits/-/inherits-2.0.3.tgz#633c2c83e3da42a502f52466022480f4208261de"
 
+is-accessor-descriptor@^0.1.6:
+  version "0.1.6"
+  resolved "https://registry.yarnpkg.com/is-accessor-descriptor/-/is-accessor-descriptor-0.1.6.tgz#a9e12cb3ae8d876727eeef3843f8a0897b5c98d6"
+  dependencies:
+    kind-of "^3.0.2"
+
+is-accessor-descriptor@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/is-accessor-descriptor/-/is-accessor-descriptor-1.0.0.tgz#169c2f6d3df1f992618072365c9b0ea1f6878656"
+  dependencies:
+    kind-of "^6.0.0"
+
+is-buffer@^1.1.5:
+  version "1.1.6"
+  resolved "https://registry.yarnpkg.com/is-buffer/-/is-buffer-1.1.6.tgz#efaa2ea9daa0d7ab2ea13a97b2b8ad51fefbe8be"
+
+is-data-descriptor@^0.1.4:
+  version "0.1.4"
+  resolved "https://registry.yarnpkg.com/is-data-descriptor/-/is-data-descriptor-0.1.4.tgz#0b5ee648388e2c860282e793f1856fec3f301b56"
+  dependencies:
+    kind-of "^3.0.2"
+
+is-data-descriptor@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/is-data-descriptor/-/is-data-descriptor-1.0.0.tgz#d84876321d0e7add03990406abbbbd36ba9268c7"
+  dependencies:
+    kind-of "^6.0.0"
+
+is-descriptor@^0.1.0:
+  version "0.1.6"
+  resolved "https://registry.yarnpkg.com/is-descriptor/-/is-descriptor-0.1.6.tgz#366d8240dde487ca51823b1ab9f07a10a78251ca"
+  dependencies:
+    is-accessor-descriptor "^0.1.6"
+    is-data-descriptor "^0.1.4"
+    kind-of "^5.0.0"
+
+is-descriptor@^1.0.0, is-descriptor@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/is-descriptor/-/is-descriptor-1.0.2.tgz#3b159746a66604b04f8c81524ba365c5f14d86ec"
+  dependencies:
+    is-accessor-descriptor "^1.0.0"
+    is-data-descriptor "^1.0.0"
+    kind-of "^6.0.2"
+
+is-extendable@^0.1.0, is-extendable@^0.1.1:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/is-extendable/-/is-extendable-0.1.1.tgz#62b110e289a471418e3ec36a617d472e301dfc89"
+
+is-extendable@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/is-extendable/-/is-extendable-1.0.1.tgz#a7470f9e426733d81bd81e1155264e3a3507cab4"
+  dependencies:
+    is-plain-object "^2.0.4"
+
+is-extglob@^2.1.0, is-extglob@^2.1.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/is-extglob/-/is-extglob-2.1.1.tgz#a88c02535791f02ed37c76a1b9ea9773c833f8c2"
+
+is-glob@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/is-glob/-/is-glob-3.1.0.tgz#7ba5ae24217804ac70707b96922567486cc3e84a"
+  dependencies:
+    is-extglob "^2.1.0"
+
+is-glob@^4.0.0:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/is-glob/-/is-glob-4.0.1.tgz#7567dbe9f2f5e2467bc77ab83c4a29482407a5dc"
+  dependencies:
+    is-extglob "^2.1.1"
+
+is-number@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-number/-/is-number-3.0.0.tgz#24fd6201a4782cf50561c810276afc7d12d71195"
+  dependencies:
+    kind-of "^3.0.2"
+
+is-plain-object@^2.0.1, is-plain-object@^2.0.3, is-plain-object@^2.0.4:
+  version "2.0.4"
+  resolved "https://registry.yarnpkg.com/is-plain-object/-/is-plain-object-2.0.4.tgz#2c163b3fafb1b606d9d17928f05c2a1c38e07677"
+  dependencies:
+    isobject "^3.0.1"
+
+is-windows@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/is-windows/-/is-windows-1.0.2.tgz#d1850eb9791ecd18e6182ce12a30f396634bb19d"
+
+isarray@1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/isarray/-/isarray-1.0.0.tgz#bb935d48582cba168c06834957a54a3e07124f11"
+
+isobject@^2.0.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/isobject/-/isobject-2.1.0.tgz#f065561096a3f1da2ef46272f815c840d87e0c89"
+  dependencies:
+    isarray "1.0.0"
+
+isobject@^3.0.0, isobject@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/isobject/-/isobject-3.0.1.tgz#4e431e92b11a9731636aa1f9c8d1ccbcfdab78df"
+
 jsonfile@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/jsonfile/-/jsonfile-4.0.0.tgz#8771aae0799b64076b76640fca058f9c10e33ecb"
   optionalDependencies:
     graceful-fs "^4.1.6"
 
+kind-of@^3.0.2, kind-of@^3.0.3, kind-of@^3.2.0:
+  version "3.2.2"
+  resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-3.2.2.tgz#31ea21a734bab9bbb0f32466d893aea51e4a3c64"
+  dependencies:
+    is-buffer "^1.1.5"
+
+kind-of@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-4.0.0.tgz#20813df3d712928b207378691a45066fae72dd57"
+  dependencies:
+    is-buffer "^1.1.5"
+
+kind-of@^5.0.0:
+  version "5.1.0"
+  resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-5.1.0.tgz#729c91e2d857b7a419a1f9aa65685c4c33f5845d"
+
+kind-of@^6.0.0, kind-of@^6.0.2:
+  version "6.0.2"
+  resolved "https://registry.yarnpkg.com/kind-of/-/kind-of-6.0.2.tgz#01146b36a6218e64e58f3a8d66de5d7fc6f6d051"
+
+lodash@^4.17.11:
+  version "4.17.11"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.11.tgz#b39ea6229ef607ecd89e2c8df12536891cac9b8d"
+
 lodash@^4.17.4:
   version "4.17.4"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
 
+map-cache@^0.2.2:
+  version "0.2.2"
+  resolved "https://registry.yarnpkg.com/map-cache/-/map-cache-0.2.2.tgz#c32abd0bd6525d9b051645bb4f26ac5dc98a0dbf"
+
+map-visit@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/map-visit/-/map-visit-1.0.0.tgz#ecdca8f13144e660f1b5bd41f12f3479d98dfb8f"
+  dependencies:
+    object-visit "^1.0.0"
+
+merge2@^1.2.3:
+  version "1.2.3"
+  resolved "https://registry.yarnpkg.com/merge2/-/merge2-1.2.3.tgz#7ee99dbd69bb6481689253f018488a1b902b0ed5"
+
+micromatch@^3.1.10:
+  version "3.1.10"
+  resolved "https://registry.yarnpkg.com/micromatch/-/micromatch-3.1.10.tgz#70859bc95c9840952f359a068a3fc49f9ecfac23"
+  dependencies:
+    arr-diff "^4.0.0"
+    array-unique "^0.3.2"
+    braces "^2.3.1"
+    define-property "^2.0.2"
+    extend-shallow "^3.0.2"
+    extglob "^2.0.4"
+    fragment-cache "^0.2.1"
+    kind-of "^6.0.2"
+    nanomatch "^1.2.9"
+    object.pick "^1.3.0"
+    regex-not "^1.0.0"
+    snapdragon "^0.8.1"
+    to-regex "^3.0.2"
+
 minimatch@^3.0.4:
   version "3.0.4"
   resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
   dependencies:
     brace-expansion "^1.1.7"
 
+mixin-deep@^1.2.0:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/mixin-deep/-/mixin-deep-1.3.1.tgz#a49e7268dce1a0d9698e45326c5626df3543d0fe"
+  dependencies:
+    for-in "^1.0.2"
+    is-extendable "^1.0.1"
+
+ms@2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
+
+nanomatch@^1.2.9:
+  version "1.2.13"
+  resolved "https://registry.yarnpkg.com/nanomatch/-/nanomatch-1.2.13.tgz#b87a8aa4fc0de8fe6be88895b38983ff265bd119"
+  dependencies:
+    arr-diff "^4.0.0"
+    array-unique "^0.3.2"
+    define-property "^2.0.2"
+    extend-shallow "^3.0.2"
+    fragment-cache "^0.2.1"
+    is-windows "^1.0.2"
+    kind-of "^6.0.2"
+    object.pick "^1.3.0"
+    regex-not "^1.0.0"
+    snapdragon "^0.8.1"
+    to-regex "^3.0.1"
+
+object-copy@^0.1.0:
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/object-copy/-/object-copy-0.1.0.tgz#7e7d858b781bd7c991a41ba975ed3812754e998c"
+  dependencies:
+    copy-descriptor "^0.1.0"
+    define-property "^0.2.5"
+    kind-of "^3.0.3"
+
+object-visit@^1.0.0:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/object-visit/-/object-visit-1.0.1.tgz#f79c4493af0c5377b59fe39d395e41042dd045bb"
+  dependencies:
+    isobject "^3.0.0"
+
+object.pick@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/object.pick/-/object.pick-1.3.0.tgz#87a10ac4c1694bd2e1cbf53591a66141fb5dd747"
+  dependencies:
+    isobject "^3.0.1"
+
 once@^1.3.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/once/-/once-1.4.0.tgz#583b1aa775961d4b113ac17d9c50baef9dd76bd1"
   dependencies:
     wrappy "1"
 
+pascalcase@^0.1.1:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/pascalcase/-/pascalcase-0.1.1.tgz#b363e55e8006ca6fe21784d2db22bd15d7917f14"
+
+path-dirname@^1.0.0:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/path-dirname/-/path-dirname-1.0.2.tgz#cc33d24d525e099a5388c0336c6e32b9160609e0"
+
 path-is-absolute@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/path-is-absolute/-/path-is-absolute-1.0.1.tgz#174b9268735534ffbc7ace6bf53a5a9e1b5c5f5f"
@@ -131,27 +602,181 @@ pify@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/pify/-/pify-3.0.0.tgz#e5a4acd2c101fdf3d9a4d07f0dbc4db49dd28176"
 
-serverless-plugin-typescript@1.1.5:
-  version "1.1.5"
-  resolved "https://registry.yarnpkg.com/serverless-plugin-typescript/-/serverless-plugin-typescript-1.1.5.tgz#a62ed1f04ea76875c72700b36b8bf95002a8d6a0"
+pify@^4.0.1:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/pify/-/pify-4.0.1.tgz#4b2cd25c50d598735c50292224fd8c6df41e3231"
+
+posix-character-classes@^0.1.0:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/posix-character-classes/-/posix-character-classes-0.1.1.tgz#01eac0fe3b5af71a2a6c02feabb8c1fef7e00eab"
+
+regex-not@^1.0.0, regex-not@^1.0.2:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/regex-not/-/regex-not-1.0.2.tgz#1f4ece27e00b0b65e0247a6810e6a85d83a5752c"
   dependencies:
-    fs-extra "^5.0.0"
-    globby "^7.0.0"
-    lodash "^4.17.4"
-    typescript "^2.2.2"
+    extend-shallow "^3.0.2"
+    safe-regex "^1.1.0"
 
-slash@^1.0.0:
-  version "1.0.0"
-  resolved "https://registry.yarnpkg.com/slash/-/slash-1.0.0.tgz#c41f2f6c39fc16d1cd17ad4b5d896114ae470d55"
+repeat-element@^1.1.2:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/repeat-element/-/repeat-element-1.1.3.tgz#782e0d825c0c5a3bb39731f84efee6b742e6b1ce"
+
+repeat-string@^1.6.1:
+  version "1.6.1"
+  resolved "https://registry.yarnpkg.com/repeat-string/-/repeat-string-1.6.1.tgz#8dcae470e1c88abc2d600fff4a776286da75e637"
+
+resolve-url@^0.2.1:
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/resolve-url/-/resolve-url-0.2.1.tgz#2c637fe77c893afd2a663fe21aa9080068e2052a"
+
+ret@~0.1.10:
+  version "0.1.15"
+  resolved "https://registry.yarnpkg.com/ret/-/ret-0.1.15.tgz#b8a4825d5bdb1fc3f6f53c2bc33f81388681c7bc"
+
+safe-regex@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/safe-regex/-/safe-regex-1.1.0.tgz#40a3669f3b077d1e943d44629e157dd48023bf2e"
+  dependencies:
+    ret "~0.1.10"
+
+serverless-plugin-typescript@1.1.7:
+  version "1.1.7"
+  resolved "https://registry.yarnpkg.com/serverless-plugin-typescript/-/serverless-plugin-typescript-1.1.7.tgz#a26bee076bf9b091c3be0e0fef17de551bf58079"
+  dependencies:
+    fs-extra "^7.0.1"
+    globby "^9.2.0"
+    lodash "^4.17.11"
+
+set-value@^0.4.3:
+  version "0.4.3"
+  resolved "https://registry.yarnpkg.com/set-value/-/set-value-0.4.3.tgz#7db08f9d3d22dc7f78e53af3c3bf4666ecdfccf1"
+  dependencies:
+    extend-shallow "^2.0.1"
+    is-extendable "^0.1.1"
+    is-plain-object "^2.0.1"
+    to-object-path "^0.3.0"
+
+set-value@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/set-value/-/set-value-2.0.0.tgz#71ae4a88f0feefbbf52d1ea604f3fb315ebb6274"
+  dependencies:
+    extend-shallow "^2.0.1"
+    is-extendable "^0.1.1"
+    is-plain-object "^2.0.3"
+    split-string "^3.0.1"
+
+slash@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/slash/-/slash-2.0.0.tgz#de552851a1759df3a8f206535442f5ec4ddeab44"
+
+snapdragon-node@^2.0.1:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/snapdragon-node/-/snapdragon-node-2.1.1.tgz#6c175f86ff14bdb0724563e8f3c1b021a286853b"
+  dependencies:
+    define-property "^1.0.0"
+    isobject "^3.0.0"
+    snapdragon-util "^3.0.1"
+
+snapdragon-util@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/snapdragon-util/-/snapdragon-util-3.0.1.tgz#f956479486f2acd79700693f6f7b805e45ab56e2"
+  dependencies:
+    kind-of "^3.2.0"
+
+snapdragon@^0.8.1:
+  version "0.8.2"
+  resolved "https://registry.yarnpkg.com/snapdragon/-/snapdragon-0.8.2.tgz#64922e7c565b0e14204ba1aa7d6964278d25182d"
+  dependencies:
+    base "^0.11.1"
+    debug "^2.2.0"
+    define-property "^0.2.5"
+    extend-shallow "^2.0.1"
+    map-cache "^0.2.2"
+    source-map "^0.5.6"
+    source-map-resolve "^0.5.0"
+    use "^3.1.0"
+
+source-map-resolve@^0.5.0:
+  version "0.5.2"
+  resolved "https://registry.yarnpkg.com/source-map-resolve/-/source-map-resolve-0.5.2.tgz#72e2cc34095543e43b2c62b2c4c10d4a9054f259"
+  dependencies:
+    atob "^2.1.1"
+    decode-uri-component "^0.2.0"
+    resolve-url "^0.2.1"
+    source-map-url "^0.4.0"
+    urix "^0.1.0"
+
+source-map-url@^0.4.0:
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/source-map-url/-/source-map-url-0.4.0.tgz#3e935d7ddd73631b97659956d55128e87b5084a3"
+
+source-map@^0.5.6:
+  version "0.5.7"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
+
+split-string@^3.0.1, split-string@^3.0.2:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/split-string/-/split-string-3.1.0.tgz#7cb09dda3a86585705c64b39a6466038682e8fe2"
+  dependencies:
+    extend-shallow "^3.0.0"
+
+static-extend@^0.1.1:
+  version "0.1.2"
+  resolved "https://registry.yarnpkg.com/static-extend/-/static-extend-0.1.2.tgz#60809c39cbff55337226fd5e0b520f341f1fb5c6"
+  dependencies:
+    define-property "^0.2.5"
+    object-copy "^0.1.0"
+
+to-object-path@^0.3.0:
+  version "0.3.0"
+  resolved "https://registry.yarnpkg.com/to-object-path/-/to-object-path-0.3.0.tgz#297588b7b0e7e0ac08e04e672f85c1f4999e17af"
+  dependencies:
+    kind-of "^3.0.2"
+
+to-regex-range@^2.1.0:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/to-regex-range/-/to-regex-range-2.1.1.tgz#7c80c17b9dfebe599e27367e0d4dd5590141db38"
+  dependencies:
+    is-number "^3.0.0"
+    repeat-string "^1.6.1"
 
-typescript@^2.2.2:
-  version "2.3.0"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.3.0.tgz#2e63e09284392bc8158a2444c33e2093795c0418"
+to-regex@^3.0.1, to-regex@^3.0.2:
+  version "3.0.2"
+  resolved "https://registry.yarnpkg.com/to-regex/-/to-regex-3.0.2.tgz#13cfdd9b336552f30b51f33a8ae1b42a7a7599ce"
+  dependencies:
+    define-property "^2.0.2"
+    extend-shallow "^3.0.2"
+    regex-not "^1.0.2"
+    safe-regex "^1.1.0"
+
+union-value@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/union-value/-/union-value-1.0.0.tgz#5c71c34cb5bad5dcebe3ea0cd08207ba5aa1aea4"
+  dependencies:
+    arr-union "^3.1.0"
+    get-value "^2.0.6"
+    is-extendable "^0.1.1"
+    set-value "^0.4.3"
 
 universalify@^0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/universalify/-/universalify-0.1.1.tgz#fa71badd4437af4c148841e3b3b165f9e9e590b7"
 
+unset-value@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/unset-value/-/unset-value-1.0.0.tgz#8376873f7d2335179ffb1e6fc3a8ed0dfc8ab559"
+  dependencies:
+    has-value "^0.3.1"
+    isobject "^3.0.0"
+
+urix@^0.1.0:
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/urix/-/urix-0.1.0.tgz#da937f7a62e21fec1fd18d49b35c2935067a6c72"
+
+use@^3.1.0:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/use/-/use-3.1.1.tgz#d50c8cac79a19fbc20f2911f56eb973f4e10070f"
+
 wrappy@1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"
diff --git a/package.json b/package.json
index c6de7b5e..0599b0ea 100644
--- a/package.json
+++ b/package.json
@@ -28,12 +28,13 @@
   ],
   "devDependencies": {
     "@types/fs-extra": "5.0.5",
-    "@types/jest": "24.0.11",
+    "@types/jest": "24.0.12",
     "@types/lodash": "4.14.123",
+    "@types/node": "12.6.2",
     "jest": "24.5.0",
-    "mock-fs": "4.8.0",
-    "rimraf": "^2.6.3",
-    "ts-jest": "24.0.1",
+    "mock-fs": "4.9.0",
+    "rimraf": "2.6.3",
+    "ts-jest": "24.0.2",
     "tslint": "5.14.0",
     "typescript": "^3.4.1"
   },
diff --git a/src/Serverless.d.ts b/src/Serverless.d.ts
new file mode 100644
index 00000000..ec7d7049
--- /dev/null
+++ b/src/Serverless.d.ts
@@ -0,0 +1,46 @@
+declare namespace Serverless {
+  interface Instance {
+    cli: {
+      log(str: string): void
+    }
+
+    config: {
+      servicePath: string
+    }
+
+    service: {
+      provider: {
+        name: string
+      }
+      functions: {
+        [key: string]: Serverless.Function
+      }
+      package: Serverless.Package
+      getAllFunctions(): string[]
+    }
+
+    pluginManager: PluginManager
+  }
+
+  interface Options {
+    function?: string
+    watch?: boolean
+    extraServicePath?: string
+  }
+
+  interface Function {
+    handler: string
+    package: Serverless.Package
+  }
+
+  interface Package {
+    include: string[]
+    exclude: string[]
+    artifact?: string
+    individually?: boolean
+  }
+
+  interface PluginManager {
+    spawn(command: string): Promise<void>
+  }
+}
\ No newline at end of file
diff --git a/src/index.ts b/src/index.ts
index 27e1769b..10fcb5e7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,50 +1,64 @@
 import * as path from 'path'
 import * as fs from 'fs-extra'
-
 import * as _ from 'lodash'
 import * as globby from 'globby'
 
-import { ServerlessOptions, ServerlessInstance, ServerlessFunction } from './types'
 import * as typescript from './typescript'
-
 import { watchFiles } from './watchFiles'
 
-// Folders
-const serverlessFolder = '.serverless'
-const buildFolder = '.build'
+const SERVERLESS_FOLDER = '.serverless'
+const BUILD_FOLDER = '.build'
 
 export class TypeScriptPlugin {
-
   private originalServicePath: string
   private isWatching: boolean
 
-  serverless: ServerlessInstance
-  options: ServerlessOptions
-  commands: { [key: string]: any }
+  serverless: Serverless.Instance
+  options: Serverless.Options
   hooks: { [key: string]: Function }
 
-  constructor(serverless: ServerlessInstance, options: ServerlessOptions) {
+  constructor(serverless: Serverless.Instance, options: Serverless.Options) {
     this.serverless = serverless
     this.options = options
 
     this.hooks = {
       'before:run:run': async () => {
         await this.compileTs()
+        await this.copyExtras()
+        await this.copyDependencies()
       },
       'before:offline:start': async () => {
         await this.compileTs()
+        await this.copyExtras()
+        await this.copyDependencies()
         this.watchAll()
       },
       'before:offline:start:init': async () => {
         await this.compileTs()
+        await this.copyExtras()
+        await this.copyDependencies()
         this.watchAll()
       },
-      'before:package:createDeploymentArtifacts': this.compileTs.bind(this),
-      'after:package:createDeploymentArtifacts': this.cleanup.bind(this),
-      'before:deploy:function:packageFunction': this.compileTs.bind(this),
-      'after:deploy:function:packageFunction': this.cleanup.bind(this),
+      'before:package:createDeploymentArtifacts': async () => {
+        await this.compileTs()
+        await this.copyExtras()
+        await this.copyDependencies(true)
+      },
+      'after:package:createDeploymentArtifacts': async () => {
+        await this.cleanup()
+      },
+      'before:deploy:function:packageFunction': async () => {
+        await this.compileTs()
+        await this.copyExtras()
+        await this.copyDependencies(true)
+      },
+      'after:deploy:function:packageFunction': async () => {
+        await this.cleanup()
+      },
       'before:invoke:local:invoke': async () => {
         const emitedFiles = await this.compileTs()
+        await this.copyExtras()
+        await this.copyDependencies()
         if (this.isWatching) {
           emitedFiles.forEach(filename => {
             const module = require.resolve(path.resolve(this.originalServicePath, filename))
@@ -55,31 +69,42 @@ export class TypeScriptPlugin {
       'after:invoke:local:invoke': () => {
         if (this.options.watch) {
           this.watchFunction()
-          this.serverless.cli.log('Waiting for changes ...')
+          this.serverless.cli.log('Waiting for changes...')
         }
       }
     }
   }
 
   get functions() {
-    return this.options.function
-      ? { [this.options.function] : this.serverless.service.functions[this.options.function] }
-      : this.serverless.service.functions
+    const { options } = this
+    const { service } = this.serverless
+
+    if (options.function) {
+      return {
+        [options.function]: service.functions[this.options.function]
+      }
+    }
+
+    return service.functions
   }
 
   get rootFileNames() {
-    return typescript.extractFileNames(this.originalServicePath, this.serverless.service.provider.name, this.functions)
+    return typescript.extractFileNames(
+      this.originalServicePath,
+      this.serverless.service.provider.name,
+      this.functions
+    )
   }
 
   prepare() {
     // exclude serverless-plugin-typescript
-    const functions = this.functions
-    for (const fnName in functions) {
-      const fn = functions[fnName]
+    for (const fnName in this.functions) {
+      const fn = this.functions[fnName]
       fn.package = fn.package || {
         exclude: [],
         include: [],
       }
+
       // Add plugin to excluded packages or an empty array if exclude is undefined
       fn.package.exclude = _.uniq([...fn.package.exclude || [], 'node_modules/serverless-plugin-typescript'])
     }
@@ -106,9 +131,7 @@ export class TypeScriptPlugin {
     this.serverless.cli.log(`Watching typescript files...`)
 
     this.isWatching = true
-    watchFiles(this.rootFileNames, this.originalServicePath, () => {
-      this.compileTs()
-    })
+    watchFiles(this.rootFileNames, this.originalServicePath, this.compileTs)
   }
 
   async compileTs(): Promise<string[]> {
@@ -119,7 +142,7 @@ export class TypeScriptPlugin {
       // Save original service path and functions
       this.originalServicePath = this.serverless.config.servicePath
       // Fake service path so that serverless will know what to zip
-      this.serverless.config.servicePath = path.join(this.originalServicePath, buildFolder)
+      this.serverless.config.servicePath = path.join(this.originalServicePath, BUILD_FOLDER)
     }
 
     const tsconfig = typescript.getTypescriptConfig(
@@ -127,34 +150,23 @@ export class TypeScriptPlugin {
       this.isWatching ? null : this.serverless.cli
     )
 
-    tsconfig.outDir = buildFolder
+    tsconfig.outDir = BUILD_FOLDER
 
     const emitedFiles = await typescript.run(this.rootFileNames, tsconfig)
-    await this.copyExtras()
     this.serverless.cli.log('Typescript compiled.')
     return emitedFiles
   }
 
+  /** Link or copy extras such as node_modules or package.include definitions */
   async copyExtras() {
-    const outPkgPath = path.resolve(path.join(buildFolder, 'package.json'))
-    const outModulesPath = path.resolve(path.join(buildFolder, 'node_modules'))
-
-    // Link or copy node_modules and package.json to .build so Serverless can
-    // exlcude devDeps during packaging
-    if (!fs.existsSync(outModulesPath)) {
-      await this.linkOrCopy(path.resolve('node_modules'), outModulesPath, 'junction')
-    }
-
-    if (!fs.existsSync(outPkgPath)) {
-      await this.linkOrCopy(path.resolve('package.json'), outPkgPath, 'file')
-    }
+    const { service } = this.serverless
 
     // include any "extras" from the "include" section
-    if (this.serverless.service.package.include && this.serverless.service.package.include.length > 0) {
-      const files = await globby(this.serverless.service.package.include)
+    if (service.package.include && service.package.include.length > 0) {
+      const files = await globby(service.package.include)
 
       for (const filename of files) {
-        const destFileName = path.resolve(path.join(buildFolder, filename))
+        const destFileName = path.resolve(path.join(BUILD_FOLDER, filename))
         const dirname = path.dirname(destFileName)
 
         if (!fs.existsSync(dirname)) {
@@ -162,45 +174,81 @@ export class TypeScriptPlugin {
         }
 
         if (!fs.existsSync(destFileName)) {
-          fs.copySync(path.resolve(filename), path.resolve(path.join(buildFolder, filename)))
+          fs.copySync(path.resolve(filename), path.resolve(path.join(BUILD_FOLDER, filename)))
         }
       }
     }
   }
 
+  /**
+   * Copy the `node_modules` folder and `package.json` files to the output
+   * directory.
+   * @param isPackaging Provided if serverless is packaging the service for deployment
+   */
+  async copyDependencies(isPackaging = false) {
+    const outPkgPath = path.resolve(path.join(BUILD_FOLDER, 'package.json'))
+    const outModulesPath = path.resolve(path.join(BUILD_FOLDER, 'node_modules'))
+
+    // copy development dependencies during packaging
+    if (isPackaging) {
+      if (fs.existsSync(outModulesPath)) {
+        fs.unlinkSync(outModulesPath)
+      }
+
+      fs.copySync(
+        path.resolve('node_modules'),
+        path.resolve(path.join(BUILD_FOLDER, 'node_modules'))
+      )
+    } else {
+      if (!fs.existsSync(outModulesPath)) {
+        await this.linkOrCopy(path.resolve('node_modules'), outModulesPath, 'junction')
+      }
+    }
+
+    // copy/link package.json
+    if (!fs.existsSync(outPkgPath)) {
+      await this.linkOrCopy(path.resolve('package.json'), outPkgPath, 'file')
+    }
+  }
+
+  /**
+   * Move built code to the serverless folder, taking into account individual
+   * packaging preferences.
+   */
   async moveArtifacts(): Promise<void> {
+    const { service } = this.serverless
+
     await fs.copy(
-      path.join(this.originalServicePath, buildFolder, serverlessFolder),
-      path.join(this.originalServicePath, serverlessFolder)
+      path.join(this.originalServicePath, BUILD_FOLDER, SERVERLESS_FOLDER),
+      path.join(this.originalServicePath, SERVERLESS_FOLDER)
     )
 
     if (this.options.function) {
-      const fn = this.serverless.service.functions[this.options.function]
-      const basename = path.basename(fn.package.artifact)
-      fn.package.artifact =  path.join(
+      const fn = service.functions[this.options.function]
+      fn.package.artifact = path.join(
         this.originalServicePath,
-        serverlessFolder,
+        SERVERLESS_FOLDER,
         path.basename(fn.package.artifact)
       )
       return
     }
 
-    if (this.serverless.service.package.individually) {
-      const functionNames = this.serverless.service.getAllFunctions()
+    if (service.package.individually) {
+      const functionNames = service.getAllFunctions()
       functionNames.forEach(name => {
-        this.serverless.service.functions[name].package.artifact = path.join(
+        service.functions[name].package.artifact = path.join(
           this.originalServicePath,
-          serverlessFolder,
-          path.basename(this.serverless.service.functions[name].package.artifact)
+          SERVERLESS_FOLDER,
+          path.basename(service.functions[name].package.artifact)
         )
       })
       return
     }
 
-    this.serverless.service.package.artifact = path.join(
+    service.package.artifact = path.join(
       this.originalServicePath,
-      serverlessFolder,
-      path.basename(this.serverless.service.package.artifact)
+      SERVERLESS_FOLDER,
+      path.basename(service.package.artifact)
     )
   }
 
@@ -209,18 +257,14 @@ export class TypeScriptPlugin {
     // Restore service path
     this.serverless.config.servicePath = this.originalServicePath
     // Remove temp build folder
-    fs.removeSync(path.join(this.originalServicePath, buildFolder))
+    fs.removeSync(path.join(this.originalServicePath, BUILD_FOLDER))
   }
 
   /**
    * Attempt to symlink a given path or directory and copy if it fails with an
    * `EPERM` error.
    */
-  private async linkOrCopy(
-    srcPath: string,
-    dstPath: string,
-    type?: 'dir' | 'junction' | 'file'
-  ): Promise<void> {
+  private async linkOrCopy(srcPath: string, dstPath: string, type?: fs.FsSymlinkType): Promise<void> {
     return fs.symlink(srcPath, dstPath, type)
       .catch(error => {
         if (error.code === 'EPERM' && error.errno === -4048) {
diff --git a/src/types.ts b/src/types.ts
deleted file mode 100644
index 4ad23338..00000000
--- a/src/types.ts
+++ /dev/null
@@ -1,39 +0,0 @@
-export interface ServerlessInstance {
-  cli: {
-    log(str: string)
-  }
-  config: {
-    servicePath: string
-  }
-  service: {
-    provider: {
-      name: string
-    }
-    functions: { [key: string]: ServerlessFunction }
-    package: ServerlessPackage
-    getAllFunctions: () => string[]
-  }
-  pluginManager: PluginManager
-}
-
-export interface ServerlessOptions {
-  function?: string
-  watch?: boolean
-  extraServicePath?: string
-}
-
-export interface ServerlessFunction {
-  handler: string
-  package: ServerlessPackage
-}
-
-export interface ServerlessPackage {
-  include: string[]
-  exclude: string[]
-  artifact?: string
-  individually?: boolean
-}
-
-export interface PluginManager {
-  spawn(command: string): Promise<void>
-}
diff --git a/src/typescript.ts b/src/typescript.ts
index f18e59b4..22f7354a 100644
--- a/src/typescript.ts
+++ b/src/typescript.ts
@@ -1,7 +1,6 @@
 import * as ts from 'typescript'
 import * as fs from 'fs-extra'
 import * as _ from 'lodash'
-import { ServerlessFunction } from './types'
 import * as path from 'path'
 
 export function makeDefaultTypescriptConfig() {
@@ -9,6 +8,7 @@ export function makeDefaultTypescriptConfig() {
     preserveConstEnums: true,
     strictNullChecks: true,
     sourceMap: true,
+    allowJs: true,
     target: ts.ScriptTarget.ES5,
     moduleResolution: ts.ModuleResolutionKind.NodeJs,
     lib: ['lib.es2015.d.ts'],
@@ -18,8 +18,7 @@ export function makeDefaultTypescriptConfig() {
   return defaultTypescriptConfig
 }
 
-export function extractFileNames(cwd: string, provider: string, functions?: { [key: string]: ServerlessFunction }): string[] {
-
+export function extractFileNames(cwd: string, provider: string, functions?: { [key: string]: Serverless.Function }): string[] {
   // The Google provider will use the entrypoint not from the definition of the
   // handler function, but instead from the package.json:main field, or via a
   // index.js file. This check reads the current package.json in the same way
@@ -53,7 +52,21 @@ export function extractFileNames(cwd: string, provider: string, functions?: { [k
       const fnName = _.last(h.split('.'))
       const fnNameLastAppearanceIndex = h.lastIndexOf(fnName)
       // replace only last instance to allow the same name for file and handler
-      return h.substring(0, fnNameLastAppearanceIndex) + 'ts'
+      const fileName = h.substring(0, fnNameLastAppearanceIndex)
+
+      // Check if the .ts files exists. If so return that to watch
+      if (fs.existsSync(path.join(cwd, fileName + 'ts'))) {
+        return fileName + 'ts'
+      }
+
+      // Check if the .js files exists. If so return that to watch
+      if (fs.existsSync(path.join(cwd, fileName + 'js'))) {
+        return fileName + 'js'
+      }
+
+      // Can't find the files. Watch will have an exception anyway. So throw one with error.
+      console.log(`Cannot locate handler - ${fileName} not found`)
+      throw new Error('Typescript compilation failed. Please ensure handlers exists with ext .ts or .js')
     })
 }
 
diff --git a/src/watchFiles.ts b/src/watchFiles.ts
index 8b8322c5..a231534a 100644
--- a/src/watchFiles.ts
+++ b/src/watchFiles.ts
@@ -1,13 +1,7 @@
 import * as typescript from './typescript'
-import * as ts from 'typescript'
 import { watchFile, unwatchFile, Stats} from 'fs'
-import { ServerlessOptions, ServerlessInstance, ServerlessFunction } from './types'
 
-export function watchFiles(
-  rootFileNames: string[],
-  originalServicePath: string,
-  cb: () => void
-) {
+export function watchFiles(rootFileNames: string[], originalServicePath: string, cb: () => void) {
   const tsConfig = typescript.getTypescriptConfig(originalServicePath)
   let watchedFiles = typescript.getSourceFiles(rootFileNames, tsConfig)
 
@@ -18,7 +12,7 @@ export function watchFiles(
   function watchCallback(curr: Stats, prev: Stats) {
     // Check timestamp
     if (+curr.mtime <= +prev.mtime) {
-        return
+      return
     }
 
     cb()
diff --git a/tests/assets/hello.ts b/tests/assets/hello.ts
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/assets/jsfile.js b/tests/assets/jsfile.js
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/assets/world.ts b/tests/assets/world.ts
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/typescript.extractFileName.test.ts b/tests/typescript.extractFileName.test.ts
index 13ca2339..82fac1d8 100644
--- a/tests/typescript.extractFileName.test.ts
+++ b/tests/typescript.extractFileName.test.ts
@@ -1,24 +1,23 @@
 import {extractFileNames} from '../src/typescript'
-import {ServerlessFunction} from '../src/types'
 import * as path from 'path'
 
-const functions: { [key: string]: ServerlessFunction } = {
+const functions: { [key: string]: Serverless.Function } = {
     hello: {
-        handler: 'my-folder/hello.handler',
+        handler: 'tests/assets/hello.handler',
         package: {
             include: [],
             exclude: []
         }
     },
     world: {
-        handler: 'my-folder/my-subfolder/world.handler',
+        handler: 'tests/assets/world.handler',
         package: {
             include: [],
             exclude: []
         }
     },
-    create: {
-        handler: 'create.create',
+    js: {
+        handler: 'tests/assets/jsfile.create',
         package: {
             include: [],
             exclude: []
@@ -32,9 +31,9 @@ describe('extractFileName', () => {
             extractFileNames(process.cwd(), 'aws', functions),
         ).toEqual(
             [
-                'my-folder/hello.ts',
-                'my-folder/my-subfolder/world.ts',
-                'create.ts',
+                'tests/assets/hello.ts',
+                'tests/assets/world.ts',
+                'tests/assets/jsfile.js',
             ],
         )
     })
diff --git a/tslint.json b/tslint.json
index 5c031f84..c5574c66 100644
--- a/tslint.json
+++ b/tslint.json
@@ -19,7 +19,8 @@
         "ban-types": false,
         "interface-name": false,
         "forin": false,
-        "no-empty-interface": false
+        "no-empty-interface": false,
+        "no-namespace": [true, "allow-declarations"]
     },
     "rulesDirectory": []
 }
\ No newline at end of file
diff --git a/yarn.lock b/yarn.lock
index 4df663f3..735f988f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -353,10 +353,10 @@
   resolved "https://registry.yarnpkg.com/@types/jest-diff/-/jest-diff-20.0.1.tgz#35cc15b9c4f30a18ef21852e255fdb02f6d59b89"
   integrity sha512-yALhelO3i0hqZwhjtcr6dYyaLoCHbAMshwtj6cGxTvHZAKXHsYGdff6E8EPw3xLKY0ELUTQ69Q1rQiJENnccMA==
 
-"@types/jest@24.0.11":
-  version "24.0.11"
-  resolved "https://registry.yarnpkg.com/@types/jest/-/jest-24.0.11.tgz#1f099bea332c228ea6505a88159bfa86a5858340"
-  integrity sha512-2kLuPC5FDnWIDvaJBzsGTBQaBbnDweznicvK7UGYzlIJP4RJR2a4A/ByLUXEyEgag6jz8eHdlWExGDtH3EYUXQ==
+"@types/jest@24.0.12":
+  version "24.0.12"
+  resolved "https://registry.yarnpkg.com/@types/jest/-/jest-24.0.12.tgz#0553dd0a5ac744e7dc4e8700da6d3baedbde3e8f"
+  integrity sha512-60sjqMhat7i7XntZckcSGV8iREJyXXI6yFHZkSZvCPUeOnEJ/VP1rU/WpEWQ56mvoh8NhC+sfKAuJRTyGtCOow==
   dependencies:
     "@types/jest-diff" "*"
 
@@ -375,6 +375,11 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-11.12.2.tgz#d7f302e74b10e9801d52852137f652d9ee235da8"
   integrity sha512-c82MtnqWB/CqqK7/zit74Ob8H1dBdV7bK+BcErwtXbe0+nUGkgzq5NTDmRW/pAv2lFtmeNmW95b0zK2hxpeklg==
 
+"@types/node@12.6.2":
+  version "12.6.2"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-12.6.2.tgz#a5ccec6abb6060d5f20d256fb03ed743e9774999"
+  integrity sha512-gojym4tX0FWeV2gsW4Xmzo5wxGjXGm550oVUII7f7G5o4BV6c7DBdiG1RRQd+y1bvqRyYtPfMK85UM95vsapqQ==
+
 "@types/stack-utils@^1.0.1":
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/@types/stack-utils/-/stack-utils-1.0.1.tgz#0a851d3bd96498fa25c33ab7278ed3bd65f06c3e"
@@ -2453,10 +2458,10 @@ mkdirp@0.x, mkdirp@^0.5.1:
   dependencies:
     minimist "0.0.8"
 
-mock-fs@4.8.0:
-  version "4.8.0"
-  resolved "https://registry.yarnpkg.com/mock-fs/-/mock-fs-4.8.0.tgz#eb0784ceba4b34c91a924a5112eeb36e1b5a9e29"
-  integrity sha512-Gwj4KnJOW15YeTJKO5frFd/WDO5Mc0zxXqL9oHx3+e9rBqW8EVARqQHSaIXznUdljrD6pvbNGW2ZGXKPEfYJfw==
+mock-fs@4.9.0:
+  version "4.9.0"
+  resolved "https://registry.yarnpkg.com/mock-fs/-/mock-fs-4.9.0.tgz#7fc0c2f82965050b2776f8eb4eb63ca53a92ff86"
+  integrity sha512-aUj0qIniTNxzGqAC61Bvro7YD37tIBnMw3wpClucUVgNBS7r6YQn/M4wuoH7SGteKz4SvC1OBeDsfpG0MYC+1Q==
 
 ms@2.0.0:
   version "2.0.0"
@@ -2974,7 +2979,7 @@ ret@~0.1.10:
   resolved "https://registry.yarnpkg.com/ret/-/ret-0.1.15.tgz#b8a4825d5bdb1fc3f6f53c2bc33f81388681c7bc"
   integrity sha512-TTlYpa+OL+vMMNG24xSlQGEJ3B/RzEfUlLct7b5G/ytav+wPrplCpVMFuwzXbkecJrb6IYo1iFb0S9v37754mg==
 
-rimraf@^2.5.4, rimraf@^2.6.2, rimraf@^2.6.3:
+rimraf@2.6.3, rimraf@^2.5.4, rimraf@^2.6.2:
   version "2.6.3"
   resolved "https://registry.yarnpkg.com/rimraf/-/rimraf-2.6.3.tgz#b2d104fe0d8fb27cf9e0a1cda8262dd3833c6cab"
   integrity sha512-mwqeW5XsA2qAejG46gYdENaxXjx9onRNCfn7L0duuP4hCuTIi/QO7PDK07KJfp1d+izWPrzEJDcSqBa0OZQriA==
@@ -3385,10 +3390,10 @@ trim-right@^1.0.1:
   resolved "https://registry.yarnpkg.com/trim-right/-/trim-right-1.0.1.tgz#cb2e1203067e0c8de1f614094b9fe45704ea6003"
   integrity sha1-yy4SAwZ+DI3h9hQJS5/kVwTqYAM=
 
-ts-jest@24.0.1:
-  version "24.0.1"
-  resolved "https://registry.yarnpkg.com/ts-jest/-/ts-jest-24.0.1.tgz#77258061cc354c3fa8616b8ac03baa0f8580f854"
-  integrity sha512-mgNZmYPuGBNgYpUzchI7vdSr6zATQI0TrSyzREnXHuPCvlW8T1DQ/fdscgx4ivS5vAMUGUaoxGdWIVHC5I8imw==
+ts-jest@24.0.2:
+  version "24.0.2"
+  resolved "https://registry.yarnpkg.com/ts-jest/-/ts-jest-24.0.2.tgz#8dde6cece97c31c03e80e474c749753ffd27194d"
+  integrity sha512-h6ZCZiA1EQgjczxq+uGLXQlNgeg02WWJBbeT8j6nyIBRQdglqbvzDoHahTEIiS6Eor6x8mK6PfZ7brQ9Q6tzHw==
   dependencies:
     bs-logger "0.x"
     buffer-from "1.x"