diff --git a/lib/class-factory.js b/lib/class-factory.js
index d5a2dd22..2b6f2534 100644
--- a/lib/class-factory.js
+++ b/lib/class-factory.js
@@ -2241,6 +2241,11 @@ function toJniObjectArray (arr, env, classHandle, setObjectArrayFunc) {
   if (arr === null) {
     return NULL;
   }
+
+  if (!(arr instanceof Array)) {
+    throw new Error("Expected an array.");
+  }
+
   const length = arr.length;
   const result = env.newObjectArray(length, classHandle, NULL);