diff --git a/retrodep/threaddep/thread.h b/retrodep/threaddep/thread.h
index 985a230e..638efd1d 100644
--- a/retrodep/threaddep/thread.h
+++ b/retrodep/threaddep/thread.h
@@ -129,7 +129,9 @@ void uae_sem_init (uae_sem_t *sem, int pshared, unsigned int value);
 
 STATIC_INLINE void uae_sem_destroy (uae_sem_t *sem)
 {
-    sem_destroy (sem->sem);
+    if(sem && sem->sem) {
+        sem_destroy (sem->sem);
+    }
 }
 
 STATIC_INLINE void uae_sem_post (uae_sem_t *sem)