diff --git a/CHANGELOG b/CHANGELOG
index d22551c579..749928397c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -3,6 +3,8 @@ git-annex (8.20210631) UNRELEASED; urgency=medium
   * assistant: Avoid unncessary git repository repair in a situation where
     git fsck gets confused about a commit that is made while it's running.
   * addurl: Avoid crashing when used on beegfs.
+  * --debug output goes to stderr again, not stdout.
+    (Reversion in version 8.20210428)
 
  -- Joey Hess <id@joeyh.name>  Wed, 30 Jun 2021 17:55:10 -0400
 
diff --git a/Messages.hs b/Messages.hs
index 7fcee28067..c85e87eb47 100644
--- a/Messages.hs
+++ b/Messages.hs
@@ -270,7 +270,7 @@ debugDisplayer = do
 	-- that are displayed at the same time from mixing together.
 	lock <- newMVar ()
 	return $ \s -> withMVar lock $ \() -> do
-		S.putStr (s <> "\n")
+		S.hPutStr stderr (s <> "\n")
 		hFlush stderr
 
 {- Should commands that normally output progress messages have that
diff --git a/doc/bugs/wanted_started_to_dump_debug_output_to_stdout_.mdwn b/doc/bugs/wanted_started_to_dump_debug_output_to_stdout_.mdwn
index 8eb54e4b2a..a078f58095 100644
--- a/doc/bugs/wanted_started_to_dump_debug_output_to_stdout_.mdwn
+++ b/doc/bugs/wanted_started_to_dump_debug_output_to_stdout_.mdwn
@@ -64,3 +64,5 @@ $> git annex --debug wanted magical
 
 [[!meta author=yoh]]
 [[!tag projects/datalad]]
+
+> All commands did. [[fixed|done]] --[[Joey]]