diff --git a/irc/commands/help.py b/irc/commands/help.py
index bb1dd58..1970337 100644
--- a/irc/commands/help.py
+++ b/irc/commands/help.py
@@ -41,7 +41,7 @@ class Help(BaseCommand):
         commands = command_handler.get_commands()
 
         dummy = Data() # dummy message to test which command classes pick up this command
-        dummy.command = command
+        dummy.command = command.lower() # lowercase command name
         dummy.is_command = True
 
         for cmnd in commands:
diff --git a/irc/data.py b/irc/data.py
index 0d0fc7b..367ac3f 100644
--- a/irc/data.py
+++ b/irc/data.py
@@ -29,5 +29,6 @@ class Data(object):
             if self.command.startswith('!') or self.command.startswith('.'):
                 self.is_command = True
                 self.command = self.command[1:] # strip '!' or '.'
+                self.command = self.command.lower() # lowercase command name
         except AttributeError:
             pass