diff --git a/packages/ember-metal/lib/error_handler.js b/packages/ember-metal/lib/error_handler.js
index d2f30c1d529..7b44539643b 100644
--- a/packages/ember-metal/lib/error_handler.js
+++ b/packages/ember-metal/lib/error_handler.js
@@ -6,7 +6,7 @@ let getStack = error => {
   let stack = error.stack;
   let message = error.message;
 
-  if (stack && !stack.includes(message)) {
+  if (stack && stack.indexOf(message) === -1) {
     stack = `${message}\n${stack}`;
   }