diff --git a/src/python.ts b/src/python.ts
index 5431681..949064e 100644
--- a/src/python.ts
+++ b/src/python.ts
@@ -194,6 +194,7 @@ export class PyObject {
    */
   get isNone() {
     return this.handle === 0 ||
+      this.handle === 0n ||
       this.handle === python.None[ProxiedPyObject].handle;
   }
 
diff --git a/test/test.ts b/test/test.ts
index 6756f36..99ce34a 100644
--- a/test/test.ts
+++ b/test/test.ts
@@ -1,4 +1,4 @@
-import { assert, assertEquals } from "./deps.ts";
+import { assert, assertEquals, assertThrows } from "./deps.ts";
 import {
   kw,
   NamedArgument,
@@ -294,3 +294,15 @@ def call(cb):
   );
   cb.destroy();
 });
+
+Deno.test("exceptions", async (t) => {
+  await t.step("simple exception", () => {
+    assertThrows(() => python.runModule("1 / 0"));
+  });
+
+  await t.step("exception with traceback", () => {
+    const np = python.import("numpy");
+    const array = np.zeros([2, 3, 4]);
+    assertThrows(() => array.shape = [3, 6]);
+  });
+});