diff --git a/src/thread/generic/SDL_syssem.c b/src/thread/generic/SDL_syssem.c
index b7a4ef493..9531bd88d 100644
--- a/src/thread/generic/SDL_syssem.c
+++ b/src/thread/generic/SDL_syssem.c
@@ -176,7 +176,9 @@ SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
                                      sem->count_lock, timeout);
     }
     --sem->waiters_count;
-    --sem->count;
+    if (retval == 0) {
+        --sem->count;
+    }
     SDL_UnlockMutex(sem->count_lock);
 
     return retval;