diff --git a/AnalyseAsm.hs b/AnalyseAsm.hs
index 8932324..a283686 100644
--- a/AnalyseAsm.hs
+++ b/AnalyseAsm.hs
@@ -68,7 +68,7 @@ parseAsmLine s
             Just [l] -> Just $ AsmFunction l
             _ -> Nothing
       where
-        labelRE = mkRegex "^([^\\.0-9].*):$"
+        labelRE = mkRegex "^([^\\.0-9][a-zA-Z0-9_]*):$"
 
     matchInc :: String -> Maybe AsmItem
     matchInc s