diff --git a/core/include/mutex.h b/core/include/mutex.h
index 01b43c063c5d8ccc119c8a3393e52ecdf2500d8b..9a29eb5f7e0ffdb0e817af44454a00302474e063 100644
--- a/core/include/mutex.h
+++ b/core/include/mutex.h
@@ -58,7 +58,7 @@ typedef struct {
  * @brief This is the value of the mutex when locked and no threads are waiting
  *        for it
  */
-#define MUTEX_LOCKED ((void *)-1)
+#define MUTEX_LOCKED ((list_node_t *)-1)
 /**
  * @endcond
  */