diff --git a/Git/Command.hs b/Git/Command.hs
index f3841c7fa6..e6cec16fb2 100644
--- a/Git/Command.hs
+++ b/Git/Command.hs
@@ -94,6 +94,12 @@ pipeNullSplit params repo = do
   where
 	sep = "\0"
 
+pipeNullSplitStrict :: [CommandParam] -> Repo -> IO [String]
+pipeNullSplitStrict params repo = do
+	s <- pipeReadStrict params repo
+	return $ filter (not . null) $ split sep s
+  where
+	sep = "\0"
 
 pipeNullSplitZombie :: [CommandParam] -> Repo -> IO [String]
 pipeNullSplitZombie params repo = leaveZombie <$> pipeNullSplit params repo
diff --git a/Git/LsTree.hs b/Git/LsTree.hs
index c61ae7faba..6e4cd8470a 100644
--- a/Git/LsTree.hs
+++ b/Git/LsTree.hs
@@ -29,15 +29,17 @@ data TreeItem = TreeItem
 	, file :: FilePath
 	} deriving Show
 
-{- Lists the complete contents of a tree. -}
+{- Lists the complete contents of a tree, with lazy output. -}
 lsTree :: Ref -> Repo -> IO [TreeItem]
-lsTree t repo = map parseLsTree <$>
-	pipeNullSplitZombie [Params "ls-tree --full-tree -z -r --", File $ show t] repo
+lsTree t repo = map parseLsTree <$> pipeNullSplitZombie ps repo
+  where
+  	ps = [Params "ls-tree --full-tree -z -r --", File $ show t]
 
 {- Lists specified files in a tree. -}
 lsTreeFiles :: Ref -> [FilePath] -> Repo -> IO [TreeItem]
-lsTreeFiles t fs repo = map parseLsTree <$>
-	pipeNullSplitZombie ([Params "ls-tree -z --", File $ show t] ++ map File fs) repo
+lsTreeFiles t fs repo = map parseLsTree <$> pipeNullSplitStrict ps repo
+  where
+  	ps = [Params "ls-tree -z --", File $ show t] ++ map File fs
 
 {- Parses a line of ls-tree output.
  - (The --long format is not currently supported.) -}
diff --git a/debian/changelog b/debian/changelog
index 75d81ff76e..8fa002604b 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -24,6 +24,8 @@ git-annex (4.20130315) UNRELEASED; urgency=low
   * webapp: Improved alerts displayed when syncing with remotes, and 
     when syncing with a remote fails.
   * webapp: Force wrap long filenames in transfer display.
+  * assistant: The ConfigMonitor left one zombie behind each time
+    it checked for changes, now fixed.
 
  -- Joey Hess <joeyh@debian.org>  Fri, 15 Mar 2013 00:10:07 -0400
 
diff --git a/doc/bugs/long_running_assistant_causes_resource_starvation_on_OSX.mdwn b/doc/bugs/long_running_assistant_causes_resource_starvation_on_OSX.mdwn
index 392090c9da..f556d16e9c 100644
--- a/doc/bugs/long_running_assistant_causes_resource_starvation_on_OSX.mdwn
+++ b/doc/bugs/long_running_assistant_causes_resource_starvation_on_OSX.mdwn
@@ -24,3 +24,7 @@ Please provide any additional information below.
 I'm really not sure what to look for next. Happy to take suggestions.
 
 [!tag /design/assistant]]
+
+> [[done]], I found the zombie leak; the ConfigMonitor was 
+> leaving one zombie every time it checked a push/pull.
+> Not a fast leak, but over time they would add up. --[[Joey]]