diff --git a/fast-tags.cabal b/fast-tags.cabal
--- a/fast-tags.cabal
+++ b/fast-tags.cabal
@@ -1,5 +1,5 @@
 name: fast-tags
-version: 0.0.3
+version: 0.0.4
 cabal-version: >= 1.8
 build-type: Simple
 synopsis: Fast incremental vi tags.
@@ -12,6 +12,10 @@
     .
     The intent is to bind it to vim's BufWrite autocommand to automatically
     keep the tags file up to date.
+    .
+    Changes since 0.0.3:
+    .
+    * Fixed bug that prevented old tags from being filered out.
     .
     Changes since 0.0.2:
     .
diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -56,15 +56,18 @@
 
     let write = if output == "-" then Text.IO.hPutStr IO.stdout
             else Text.IO.writeFile output
-
-    -- Turns out GHC will not float out the T.pack and it makes a big
-    -- performance difference.
-    let textFns = Set.fromList $ map (T.pack . ('\t':)) inputs
-        filtered = filter (not . isNewTag textFns) oldTags
-    write $ T.unlines $ merge (List.sort (map showTag newTags)) filtered
+    write $ T.unlines (mergeTags inputs oldTags newTags)
     where
     usage msg = putStr (GetOpt.usageInfo msg options)
         >> System.Exit.exitSuccess
+
+mergeTags :: [FilePath] -> [Text] -> [Pos TagVal] -> [Text]
+mergeTags inputs old new =
+    merge (List.sort (map showTag new)) (filter (not . isNewTag textFns) old)
+    where
+    -- Turns out GHC will not float out the T.pack and it makes a big
+    -- performance difference.
+    textFns = Set.fromList $ map T.pack inputs
 
 data Flag = Output FilePath | Verbose
     deriving (Eq, Show)
diff --git a/src/T.hs b/src/T.hs
--- a/src/T.hs
+++ b/src/T.hs
@@ -1,11 +1,4 @@
-{-# LANGUAGE GADTs #-}
 module T where
 
-
-數字 :: Int
-數字 = 2
-
-(·) = (.)
-
-data X where
-    A, B :: X
+f :: X -> Y
+f = id