diff --git a/lib/repl.js b/lib/repl.js
index 11ee6f58216..0f93bfdc40a 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -217,7 +217,7 @@ function REPLServer(prompt,
 
   self.setPrompt(prompt !== undefined ? prompt : '> ');
 
-  this.commands = {};
+  this.commands = Object.create(null);
   defineDefaultCommands(this);
 
   // figure out which "writer" function to use
diff --git a/test/parallel/test-repl.js b/test/parallel/test-repl.js
index 94d6bca283c..65affa9b948 100644
--- a/test/parallel/test-repl.js
+++ b/test/parallel/test-repl.js
@@ -194,6 +194,10 @@ function error_test() {
     // the error message
     { client: client_unix, send: '.invalid_repl_command',
       expect: 'Invalid REPL keyword\n' + prompt_unix },
+    // this makes sure that we don't crash when we use an inherited property as
+    // a REPL command
+    { client: client_unix, send: '.toString',
+      expect: 'Invalid REPL keyword\n' + prompt_unix },
   ]);
 }