diff --git a/src/thread/pthread/SDL_sysmutex.c b/src/thread/pthread/SDL_sysmutex.c
index 07d35cfb9..79dba1331 100644
--- a/src/thread/pthread/SDL_sysmutex.c
+++ b/src/thread/pthread/SDL_sysmutex.c
@@ -141,7 +141,8 @@ void SDL_UnlockMutex(SDL_Mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS // clang do
                 pthread_mutex_unlock(&mutex->id);
             }
         } else {
-            return SDL_SetError("mutex not owned by this thread");
+            SDL_SetError("mutex not owned by this thread");
+            return;
         }
 
 #else