diff --git a/scripts/stackstorm.js b/scripts/stackstorm.js
index 0de51c0..d7e27f8 100644
--- a/scripts/stackstorm.js
+++ b/scripts/stackstorm.js
@@ -321,8 +321,11 @@ module.exports = function(robot) {
     result = command_factory.getMatchingCommand(command);
 
     if (!result) {
-      // No command found
-      return;
+      if (command.startsWith("help")) {
+          return;
+      }
+      var message = util.format(_.sample(ERROR_MESSAGES), "Command not found: " + command);
+      return msg.send(message);
     }
 
     command_name = result[0];