diff --git a/lib/readline.js b/lib/readline.js
index 7534f8785f..e0d801e87f 100644
--- a/lib/readline.js
+++ b/lib/readline.js
@@ -48,7 +48,7 @@ function Interface(input, output, completer) {
   completer = completer || function() { return []; };
 
   if (typeof completer !== 'function') {
-    throw new TypeError("Argument 'completer' must be a function");
+    throw new TypeError('Argument \'completer\' must be a function');
   }
 
   var self = this;
@@ -207,7 +207,7 @@ Interface.prototype._refreshLine = function() {
 
   // Force terminal to allocate a new line
   if (lineCols === 0) {
-    this.output.write(" ");
+    this.output.write(' ');
   }
 
   // Move cursor to original position.