diff --git a/cogs/alias.py b/cogs/alias.py
index 32269006e..2f80c9f5b 100644
--- a/cogs/alias.py
+++ b/cogs/alias.py
@@ -24,8 +24,13 @@ class Alias:
 
            Example: !alias add test flip @Twentysix"""
         server = ctx.message.server
-        if self.get_prefix(to_execute) is False:
-            to_execute = self.bot.command_prefix[0] + to_execute
+        if self.part_of_existing_command(command, server.id):
+            await self.bot.say('I can\'t safely add an alias that starts with '
+                               'an existing command or alias. Sry <3')
+            return
+        prefix = self.get_prefix(to_execute)
+        if prefix is not None:
+            to_execute = to_execute[len(prefix):]
         if server.id not in self.aliases:
             self.aliases[server.id] = {}
         if command not in self.bot.commands:
@@ -83,14 +88,32 @@ class Alias:
         prefix = self.get_prefix(msg)
 
         if prefix and server.id in self.aliases:
-            aliaslist = self.aliases[server.id]
-            alias = msg[len(prefix):].split(" ")[0]
-            args = msg[len(self.first_word(message.content)):]
-            if alias in aliaslist.keys():
-                content = aliaslist[alias] + args
-                new_message = message
-                new_message.content = content
-                await self.bot.process_commands(new_message)
+            for alias in self.aliases[server.id]:
+                if msg[len(prefix):].startswith(alias):
+                    new_command = self.aliases[server.id][alias]
+                    args = message.content[len(prefix+alias):]
+                    message.content = prefix + new_command + args
+                    await self.bot.process_commands(message)
+
+    def part_of_existing_command(self, alias, server):
+        '''Command or alias'''
+        for command in self.bot.commands:
+            if alias.startswith(command):
+                return True
+        if server not in self.aliases:
+            return False
+        for aname in self.aliases[server]:
+            if aname.startswith(alias):
+                return True
+        return False
+
+    def remove_old(self):
+        for sid in self.aliases:
+            for aliasname, alias in self.aliases[sid].items():
+                prefix = self.get_prefix(alias)
+                if prefix is not None:
+                    self.aliases[sid][aliasname] = alias[len(prefix):]
+        fileIO("data/alias/aliases.json", "save", self.aliases)
 
     def first_word(self, msg):
         return msg.split(" ")[0]
@@ -99,7 +122,7 @@ class Alias:
         for p in self.bot.command_prefix:
             if msg.startswith(p):
                 return p
-        return False
+        return None
 
 
 def check_folder():
@@ -121,5 +144,6 @@ def setup(bot):
     check_folder()
     check_file()
     n = Alias(bot)
+    n.remove_old()
     bot.add_listener(n.check_aliases, "on_message")
     bot.add_cog(n)