diff --git a/CHANGELOG b/CHANGELOG
index fcc69d1ee8..7e12578c9a 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,6 +6,9 @@ git-annex (6.20180808) UNRELEASED; urgency=medium
     Affected commands: find, add, whereis, drop, copy, move, get
   * Make metadata --batch combined with matching options refuse to run,
     since it does not seem worth supporting that combination.
+  * v6 add: Take advantage of improved SIGPIPE handler in git 2.5 to
+    speed up the clean filter by not reading the file content from the
+    pipe. This also avoids git buffering the whole file content in memory.
 
  -- Joey Hess <id@joeyh.name>  Wed, 08 Aug 2018 11:24:08 -0400
 
diff --git a/Command/Smudge.hs b/Command/Smudge.hs
index 1644ee2577..cfd327c8d0 100644
--- a/Command/Smudge.hs
+++ b/Command/Smudge.hs
@@ -16,6 +16,7 @@ import Annex.Ingest
 import Annex.CatFile
 import Logs.Location
 import qualified Database.Keys
+import qualified Git.BuildVersion
 import Git.FilePath
 import Backend
 
@@ -68,7 +69,7 @@ smudge file = do
 
 -- Clean filter is fed file content on stdin, decides if a file
 -- should be stored in the annex, and outputs a pointer to its
--- injested content.
+-- injested content if so. Otherwise, the original content.
 clean :: FilePath -> CommandStart
 clean file = do
 	b <- liftIO $ B.hGetContents stdin
@@ -76,10 +77,18 @@ clean file = do
 		then liftIO $ B.hPut stdout b
 		else ifM (shouldAnnex file)
 			( do
-				-- Even though we ingest the actual file,
-				-- and not stdin, we need to consume all
-				-- stdin, or git will get annoyed.
-				B.length b `seq` return ()
+				-- Before git 2.5, failing to consume all
+				-- stdin here would cause a SIGPIPE and
+				-- crash it.
+				-- Newer git catches the signal and
+				-- stops sending, which is much faster.
+				-- (Also, git seems to forget to free memory
+				-- when sending the file, so the less we
+				-- let it send, the less memory it will
+				-- waste.)
+				if Git.BuildVersion.older "2.5"
+					then B.length b `seq` return ()
+					else liftIO $ hClose stdin
 				-- Look up the backend that was used
 				-- for this file before, so that when
 				-- git re-cleans a file its backend does
diff --git a/doc/todo/smudge.mdwn b/doc/todo/smudge.mdwn
index 3a980b10a2..3ebb92b0ff 100644
--- a/doc/todo/smudge.mdwn
+++ b/doc/todo/smudge.mdwn
@@ -65,16 +65,16 @@ git-annex should use smudge/clean filters.
 * When git runs the smudge filter, it buffers all its output in ram before
   writing it to a file. So, checking out a branch with a large v6 unlocked files
   can cause git to use a lot of memory.
-  (This needs to be fixed in git, but my proposed interface in
+
+  This needs to be fixed in git, but my proposed interface in
   <http://thread.gmane.org/gmane.comp.version-control.git/294425> would
   avoid the problem for git checkout, since it would use the new interface
-  and not the smudge filter.)
+  and not the smudge filter.
 
-* When `git add` is run with a large file, it allocates memory for
-  the whole file content, even though it's only going
-  to stream it to the clean filter. My proposed smudge/clean
-  interface patch also fixed this problem, since it made git not read
-  the file at all.
+  Last verified with git 2.18 in 2018. 
+
+  To check: Does the long-running filter process interface have the same
+  problem?
 
 * Eventually (but not yet), make v6 the default for new repositories.
   Note that the assistant forces repos into direct mode; that will need to
diff --git a/doc/todo/smudge/comment_12_a4712d510432931062406c4e256f04b1._comment b/doc/todo/smudge/comment_12_a4712d510432931062406c4e256f04b1._comment
new file mode 100644
index 0000000000..cfa1be8bca
--- /dev/null
+++ b/doc/todo/smudge/comment_12_a4712d510432931062406c4e256f04b1._comment
@@ -0,0 +1,11 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""re: Git 2.5 allows smudge filters to not read all of stdin"""
+ date="2018-08-09T22:11:00Z"
+ content="""
+@torarnv thanks for pointing that out.. I finally got around to verifying
+that, and was able to speed up the smudge filter. Also this avoids the
+problem that git for some reason buffers the whole file content in memory
+when it sends it to the smudge filter, which is a pretty bad memory leak in git
+that no longer affects this.
+"""]]