diff --git a/lib/repl.js b/lib/repl.js
index 420fde45eb6a6b..4e2356135708ea 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -611,9 +611,7 @@ REPLServer.prototype.complete = function(line, callback) {
       if (!expr) {
         // If context is instance of vm.ScriptContext
         // Get global vars synchronously
-        if (this.useGlobal ||
-            this.context.constructor &&
-            this.context.constructor.name === 'Context') {
+        if (this.useGlobal || vm.isContext(this.context)) {
           var contextProto = this.context;
           while (contextProto = Object.getPrototypeOf(contextProto)) {
             completionGroups.push(Object.getOwnPropertyNames(contextProto));
diff --git a/test/parallel/test-repl-tab-complete.js b/test/parallel/test-repl-tab-complete.js
index 659c8046a98173..6fe62f39fc91b6 100644
--- a/test/parallel/test-repl-tab-complete.js
+++ b/test/parallel/test-repl-tab-complete.js
@@ -206,3 +206,13 @@ testMe.complete('require(\'n', function(error, data) {
   assert.strictEqual(error, null);
   assert.deepEqual(data, [['net'], 'n']);
 });
+
+// Make sure tab completion works on context properties
+putIn.run(['.clear']);
+
+putIn.run([
+  'var custom = "test";'
+]);
+testMe.complete('cus', function(error, data) {
+  assert.deepEqual(data, [['custom'], 'cus']);
+});