diff --git a/Command/DropUnused.hs b/Command/DropUnused.hs
index c6a28663ec..932a8b8635 100644
--- a/Command/DropUnused.hs
+++ b/Command/DropUnused.hs
@@ -27,12 +27,16 @@ command = [repoCommand "dropunused" (paramRepeating paramNumber) seek
 	"drop unused file content"]
 
 seek :: [CommandSeek]
-seek = [withStrings start]
+seek = [withUnusedMap]
 
-{- Drops unused content by number. -} 
-start :: CommandStartString
-start s = notBareRepo $ do
+{- Read unusedlog once, and pass the map to each start action. -}
+withUnusedMap :: CommandSeek
+withUnusedMap params = do
 	m <- readUnusedLog
+	return $ map (start m) params
+
+start :: M.Map String Key -> CommandStartString
+start m s = notBareRepo $ do
 	case M.lookup s m of
 		Nothing -> return Nothing
 		Just key -> do
diff --git a/debian/changelog b/debian/changelog
index 7bb5bd8d21..9235c3ca33 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -17,6 +17,7 @@ git-annex (0.20110321) UNRELEASED; urgency=low
   * Fix space leak in fsck and drop commands.
   * migrate: Bugfix for case when migrating a file results in a key that
     is already present in .git/annex/objects.
+  * dropunused: Significantly sped up; only read unused log file once.
 
  -- Joey Hess <joeyh@debian.org>  Tue, 22 Mar 2011 16:52:00 -0400