diff --git a/Shakefile.hs b/Shakefile.hs
--- a/Shakefile.hs
+++ b/Shakefile.hs
@@ -36,8 +36,8 @@
   -- | sanity
   --
   fake "." pats "sanity" $ const $
-    need [ fakeFile "build-error", fakeFile "lint" ]
+    need [ "build-error", "lint" ]
 
   -- | Default things to run.
   --
-  want [ fakeFile "sanity", fakeFile "format" ]
+  want [ "sanity", "format" ]
diff --git a/shakers.cabal b/shakers.cabal
--- a/shakers.cabal
+++ b/shakers.cabal
@@ -1,5 +1,5 @@
 name:                  shakers
-version:               0.0.17
+version:               0.0.18
 synopsis:              Shake helpers.
 description:           Primitive helpers for Shake files.
 homepage:              https://github.com/swift-nav/shakers
diff --git a/src/Development/Shakers.hs b/src/Development/Shakers.hs
--- a/src/Development/Shakers.hs
+++ b/src/Development/Shakers.hs
@@ -40,7 +40,6 @@
   , fake
   , meta
   , preprocess
-  , mirror
   , getHashedVersion
   , hsRules
   , stackRules
@@ -306,21 +305,12 @@
 preprocess :: FilePattern -> FilePath -> Action [(String, String)] -> Rules ()
 preprocess target file macros =
   target %> \out -> do
-    need [ file ]
+    alwaysRerun
     let f k v = "-D" <> k <> "=" <> v
     macros' <- macros
     content <- m4 $ file : (uncurry f <$> macros')
     writeFileChanged out content
 
--- | Mirror files to the mirror directory.
---
-mirror :: FilePath -> [FilePattern] -> Rules ()
-mirror dir pats =
-  fake dir pats "mirror" $ mapM_ $ \file -> do
-    dir' <- mirrorDir
-    liftIO $ createDirectoryIfMissing True $ dropFileName (dir' </> file)
-    copyFileChanged file (dir' </> file)
-
 -- | Build a hash version from a directory and file pattern.
 --
 getHashedVersion :: FilePath -> [FilePattern] -> Action String
@@ -501,13 +491,14 @@
 dockerRules dir pats = do
   -- | mirror
   --
-  mirror dir pats
-
-  -- | wipe
-  --
-  phony "wipe" $ do
+  phony "mirror" $ do
     dir' <- mirrorDir
     liftIO $ removeFiles dir' [ "//*" ]
+    files <- getDirectoryFiles dir pats
+    forM_ files $ \file ->
+      liftIO $ do
+        createDirectoryIfMissing True $ dropFileName (dir' </> file)
+        copyFile file (dir' </> file)
 
   -- | docker:login
   --