diff --git a/ChangeLog b/ChangeLog
index a78bdfd85..e2acdb50f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2025-04-08  Wolfgang Lux  <wolfgang.lux@gmail.com>
+
+	* Source/NSOperation.m (_thread): Fix potential deadlock when
+	exiting a thread.
+
 2025-04-01 Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/NSOrderedSet.m: Fix for git issue #500
diff --git a/Source/NSOperation.m b/Source/NSOperation.m
index a902a455c..ff03189b7 100644
--- a/Source/NSOperation.m
+++ b/Source/NSOperation.m
@@ -1043,12 +1043,12 @@ static NSOperationQueue *mainQueue = nil;
 	  if ([internal->starting count] == 0)
 	    {
 	      // Idle for 5 seconds ... exit thread.
+	      [internal->cond unlock];
 	      [[[NSThread currentThread] threadDictionary]
 		removeObjectForKey: threadKey];
 	      [internal->lock lock];
 	      internal->threadCount--;
 	      [internal->lock unlock];
-	      [internal->cond unlock];
 	      break;
 	    }
 	  /* An operation was added in the gap between the failed wait for