diff --git a/lib/smalloc.js b/lib/smalloc.js
index ba042c6c4c..fd82ba8c42 100644
--- a/lib/smalloc.js
+++ b/lib/smalloc.js
@@ -86,6 +86,8 @@ function dispose(obj) {
     throw new TypeError('obj must be an Object');
   if (util.isBuffer(obj))
     throw new TypeError('obj cannot be a Buffer');
+  if (!smalloc.hasExternalData(obj))
+    throw new Error('obj has no external array data');
 
   smalloc.dispose(obj);
 }
diff --git a/test/simple/test-smalloc.js b/test/simple/test-smalloc.js
index ea6f7bf4ad..091f5aa7e0 100644
--- a/test/simple/test-smalloc.js
+++ b/test/simple/test-smalloc.js
@@ -314,11 +314,15 @@ for (var i = 0; i < 5; i++)
 
 // only allow object to be passed to dispose
 assert.throws(function() {
-  alloc.dispose(null);
+  smalloc.dispose(null);
 });
 
 
 // can't dispose a Buffer
 assert.throws(function() {
-  alloc.dispose(new Buffer());
+  smalloc.dispose(new Buffer());
+});
+
+assert.throws(function() {
+  smalloc.dispose({});
 });