diff --git a/test/parallel/test-readline-interface.js b/test/parallel/test-readline-interface.js
index 2dff11f2a27e72..b941c8d6eae88c 100644
--- a/test/parallel/test-readline-interface.js
+++ b/test/parallel/test-readline-interface.js
@@ -366,6 +366,20 @@ function isWarned(emitter) {
       type: TypeError,
       code: 'ERR_INVALID_OPT_VALUE'
     });
+
+    common.mustCall(function() {
+      readline.createInterface({
+        input: fi,
+        completer: ''
+      });
+    })();
+
+    common.mustCall(function() {
+      readline.createInterface({
+        input: fi,
+        completer: false
+      });
+    })();
   }
 
   // Constructor throws if historySize is not a positive number