diff --git a/arangod/Indexes/IndexFactory.cpp b/arangod/Indexes/IndexFactory.cpp
index bc240995ceca..f3688940596b 100644
--- a/arangod/Indexes/IndexFactory.cpp
+++ b/arangod/Indexes/IndexFactory.cpp
@@ -581,4 +581,34 @@ Result IndexFactory::enhanceJsonIndexFulltext(VPackSlice definition,
   return res;
 }
 
+/// @brief enhances the json of a fulltext index
+Result IndexFactory::enhanceJsonIndexZkd(VPackSlice definition,
+                                              VPackBuilder& builder, bool create) {
+  if (auto fieldValueTypes = definition.get("fieldValueTypes");
+      !fieldValueTypes.isString() || !fieldValueTypes.isEqualString("double")) {
+    return Result(
+        TRI_ERROR_BAD_PARAMETER,
+        "zkd index requires `fieldValueTypes` to be set to `double` - future "
+        "releases might lift this requirement");
+  }
+
+  builder.add("fieldValueTypes", VPackValue("double"));
+  Result res = processIndexFields(definition, builder, 1, INT_MAX, create, false);
+
+  if (res.ok()) {
+    if (auto isSparse = definition.get(StaticStrings::IndexSparse).isTrue(); isSparse) {
+      return Result(TRI_ERROR_BAD_PARAMETER,
+                    "zkd index does not support sparse property");
+    }
+
+    processIndexUniqueFlag(definition, builder);
+
+    bool bck = basics::VelocyPackHelper::getBooleanValue(definition, StaticStrings::IndexInBackground,
+                                                         false);
+    builder.add(StaticStrings::IndexInBackground, VPackValue(bck));
+  }
+
+  return res;
+}
+
 }  // namespace arangodb
diff --git a/arangod/Indexes/IndexFactory.h b/arangod/Indexes/IndexFactory.h
index 74d18c7eab64..463ee215a478 100644
--- a/arangod/Indexes/IndexFactory.h
+++ b/arangod/Indexes/IndexFactory.h
@@ -157,11 +157,15 @@ class IndexFactory {
   static Result enhanceJsonIndexGeo(arangodb::velocypack::Slice definition,
                                     arangodb::velocypack::Builder& builder, bool create,
                                     int minFields, int maxFields);
-  
+
   /// @brief enhances the json of a fulltext index
   static Result enhanceJsonIndexFulltext(arangodb::velocypack::Slice definition,
                                          arangodb::velocypack::Builder& builder, bool create);
 
+  /// @brief enhances the json of a zkd index
+  static Result enhanceJsonIndexZkd(arangodb::velocypack::Slice definition,
+                                         arangodb::velocypack::Builder& builder, bool create);
+
  protected:
   /// @brief clear internal factory/normalizer maps
   void clear();
diff --git a/arangod/RocksDBEngine/RocksDBIndexFactory.cpp b/arangod/RocksDBEngine/RocksDBIndexFactory.cpp
index bfd3135c6374..1f5439b25ad8 100644
--- a/arangod/RocksDBEngine/RocksDBIndexFactory.cpp
+++ b/arangod/RocksDBEngine/RocksDBIndexFactory.cpp
@@ -295,13 +295,7 @@ struct ZkdIndexFactory : public DefaultIndexFactory {
                      arangodb::velocypack::Value(std::to_string(TRI_NewTickServer())));
     }
 
-    if (auto isSparse = definition.get(StaticStrings::IndexSparse).isTrue(); isSparse) {
-      THROW_ARANGO_EXCEPTION_MESSAGE(
-          TRI_ERROR_BAD_PARAMETER,
-          "zkd index does not support sparse property");
-    }
-
-    return IndexFactory::enhanceJsonIndexGeneric(definition, normalized, isCreation);
+    return IndexFactory::enhanceJsonIndexZkd(definition, normalized, isCreation);
   }
 };
 
diff --git a/tests/js/server/aql/aql-optimizer-zkdindex-multi.js b/tests/js/server/aql/aql-optimizer-zkdindex-multi.js
index 97bc0802d5e5..85ce9db2846e 100644
--- a/tests/js/server/aql/aql-optimizer-zkdindex-multi.js
+++ b/tests/js/server/aql/aql-optimizer-zkdindex-multi.js
@@ -100,7 +100,7 @@ function optimizerRuleZkd2dIndexTestSuite() {
     let testObject = {
         setUpAll: function () {
             col = db._create(colName);
-            col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y', 'z', 'a.w']});
+            col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y', 'z', 'a.w'], fieldValueTypes: 'double'});
             db._query(aql`
                 FOR x IN 0..10
                 FOR y IN 0..10
diff --git a/tests/js/server/aql/aql-optimizer-zkdindex-restricted.js b/tests/js/server/aql/aql-optimizer-zkdindex-restricted.js
new file mode 100644
index 000000000000..8cb64c542670
--- /dev/null
+++ b/tests/js/server/aql/aql-optimizer-zkdindex-restricted.js
@@ -0,0 +1,74 @@
+/* global AQL_EXPLAIN, AQL_EXECUTE */
+////////////////////////////////////////////////////////////////////////////////
+/// DISCLAIMER
+///
+/// Copyright 2021-2021 ArangoDB GmbH, Cologne, Germany
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///     http://www.apache.org/licenses/LICENSE-2.0
+///
+/// Unless required by applicable law or agreed to in writing, software
+/// distributed under the License is distributed on an "AS IS" BASIS,
+/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+/// See the License for the specific language governing permissions and
+/// limitations under the License.
+///
+/// Copyright holder is ArangoDB GmbH, Cologne, Germany
+///
+/// @author Tobias Gödderz
+////////////////////////////////////////////////////////////////////////////////
+
+'use strict';
+
+const jsunity = require("jsunity");
+const arangodb = require("@arangodb");
+const internal = require("internal");
+const db = arangodb.db;
+const {assertEqual} = jsunity.jsUnity.assertions;
+
+function optimizerRuleZkd2dIndexTestSuite() {
+    const colName = 'UnitTestZkdIndexCollection';
+    let col;
+
+    return {
+        setUpAll: function () {
+            col = db._create(colName);
+        },
+
+        tearDownAll: function () {
+            col.drop();
+        },
+
+        testNoFieldValueTypes: function () {
+            try {
+                col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y']});
+            } catch (e) {
+                assertEqual(e.errorNum, internal.errors.ERROR_BAD_PARAMETER.code);
+            }
+        },
+
+        testSparseProperty: function () {
+            try {
+                col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y'], fieldValueTypes: 'double', sparse: true});
+            } catch (e) {
+                assertEqual(e.errorNum, internal.errors.ERROR_BAD_PARAMETER.code);
+            }
+        },
+
+        testArrayExpansions: function () {
+            try {
+                col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x[*]', 'y'], fieldValueTypes: 'double'});
+            } catch (e) {
+                assertEqual(e.errorNum, internal.errors.ERROR_BAD_PARAMETER.code);
+            }
+        }
+
+    };
+}
+
+jsunity.run(optimizerRuleZkd2dIndexTestSuite);
+
+return jsunity.done();
diff --git a/tests/js/server/aql/aql-optimizer-zkdindex-unique.js b/tests/js/server/aql/aql-optimizer-zkdindex-unique.js
index 5976e11dbe8f..eb3ab7a14101 100644
--- a/tests/js/server/aql/aql-optimizer-zkdindex-unique.js
+++ b/tests/js/server/aql/aql-optimizer-zkdindex-unique.js
@@ -42,7 +42,13 @@ function optimizerRuleZkd2dIndexTestSuite() {
     return {
         setUpAll: function () {
             col = db._create(colName);
-            col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y'], unique: true});
+            col.ensureIndex({
+                type: 'zkd',
+                name: 'zkdIndex',
+                fields: ['x', 'y'],
+                unique: true,
+                fieldValueTypes: 'double'
+            });
             // Insert 1001 points
             // (-500, -499.5), (-499.1, -499.4), ..., (0, 0.5), ..., (499.9, 500.4), (500, 500.5)
             db._query(aql`
diff --git a/tests/js/server/aql/aql-optimizer-zkdindex.js b/tests/js/server/aql/aql-optimizer-zkdindex.js
index d6795221ade9..a75f21427856 100644
--- a/tests/js/server/aql/aql-optimizer-zkdindex.js
+++ b/tests/js/server/aql/aql-optimizer-zkdindex.js
@@ -41,7 +41,7 @@ function optimizerRuleZkd2dIndexTestSuite() {
     return {
         setUpAll: function () {
             col = db._create(colName);
-            col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y']});
+            col.ensureIndex({type: 'zkd', name: 'zkdIndex', fields: ['x', 'y'], fieldValueTypes: 'double'});
             // Insert 1001 points
             // (-500, -499.5), (-499.1, -499.4), ..., (0, 0.5), ..., (499.9, 500.4), (500, 500.5)
             db._query(aql`