diff --git a/Annex/LockPool/PosixOrPid.hs b/Annex/LockPool/PosixOrPid.hs
index ecf96d51fb..74ac3f1781 100644
--- a/Annex/LockPool/PosixOrPid.hs
+++ b/Annex/LockPool/PosixOrPid.hs
@@ -47,8 +47,14 @@ tryLockExclusive :: Maybe FileMode -> LockFile -> Annex (Maybe LockHandle)
 tryLockExclusive m f = tryPidLock m f $ Posix.tryLockExclusive m f
 
 checkLocked :: LockFile -> Annex (Maybe Bool)
-checkLocked f = Posix.checkLocked f
-	`pidLockCheck` Pid.checkLocked
+checkLocked f = Posix.checkLocked f `pidLockCheck` checkpid
+  where
+	checkpid pidlock = do
+		v <- Pid.checkLocked pidlock
+		case v of
+			-- Only return true when the posix lock file exists.
+			Just _ -> Posix.checkLocked f
+			Nothing -> return Nothing
 
 getLockStatus :: LockFile -> Annex LockStatus
 getLockStatus f = Posix.getLockStatus f
diff --git a/debian/changelog b/debian/changelog
index 721c5b3aa3..f49c1281e7 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,7 @@
 git-annex (6.20160230) UNRELEASED; urgency=medium
 
   * metadata: Added -r to remove all current values of a field.
+  * Fix data loss that can occur when annex.pidlock is set in a repository.
 
  -- Joey Hess <id@joeyh.name>  Mon, 29 Feb 2016 13:00:30 -0400
 
diff --git a/doc/bugs/thread_blocked_indefinitely_in_an_STM_transaction__while_moving_within__a_local_clone/comment_2_aa8c82f27965df44e69fd06b34be0ece._comment b/doc/bugs/thread_blocked_indefinitely_in_an_STM_transaction__while_moving_within__a_local_clone/comment_2_aa8c82f27965df44e69fd06b34be0ece._comment
new file mode 100644
index 0000000000..2c06811d8a
--- /dev/null
+++ b/doc/bugs/thread_blocked_indefinitely_in_an_STM_transaction__while_moving_within__a_local_clone/comment_2_aa8c82f27965df44e69fd06b34be0ece._comment
@@ -0,0 +1,11 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 2"""
+ date="2016-03-01T16:11:37Z"
+ content="""
+A worse problem with annex.pidlock is that it completly broke checking
+whether a key is present in the repository. That could lead to data loss
+when eg, moving --to a repo with annex.pidlock set.
+
+I've fixed that related bug.
+"""]]