diff --git a/src/js/sandbox/commands.js b/src/js/sandbox/commands.js
index 7f4e359d..953d4084 100644
--- a/src/js/sandbox/commands.js
+++ b/src/js/sandbox/commands.js
@@ -15,12 +15,12 @@ var Warning = Errors.Warning;
 var CommandResult = Errors.CommandResult;
 
 var instantCommands = [
-  [/^ls/, function() {
+  [/^ls( |$)/, function() {
     throw new CommandResult({
       msg: intl.str('ls-command')
     });
   }],
-  [/^cd/, function() {
+  [/^cd( |$)/, function() {
     throw new CommandResult({
       msg: intl.str('cd-command')
     });