diff --git a/reactos/win32ss/user/ntuser/message.c b/reactos/win32ss/user/ntuser/message.c
index 4702c83bc4e..4dbe59f307c 100644
--- a/reactos/win32ss/user/ntuser/message.c
+++ b/reactos/win32ss/user/ntuser/message.c
@@ -2019,7 +2019,7 @@ NtUserPostThreadMessage(DWORD idThread,
                         WPARAM wParam,
                         LPARAM lParam)
 {
-    BOOL ret;
+    BOOL ret = FALSE;
     PETHREAD peThread;
     PTHREADINFO pThread;
     NTSTATUS Status;