diff --git a/addon/is-computed.js b/addon/is-computed.js
index 04b0ae8..897ea20 100644
--- a/addon/is-computed.js
+++ b/addon/is-computed.js
@@ -1,5 +1,6 @@
 import ComputedProperty from '@ember/object/computed';
 
 export default function(key) {
-  return key instanceof ComputedProperty;
+  return key instanceof ComputedProperty ||
+    typeof key === 'function' && '_getter' in key;
 }