diff --git a/api/source/mk_player.cpp b/api/source/mk_player.cpp
index f4b6bf7c..a3dd4b9f 100755
--- a/api/source/mk_player.cpp
+++ b/api/source/mk_player.cpp
@@ -178,7 +178,7 @@ API_EXPORT void API_CALL mk_player_seekto(mk_player ctx, float progress) {
 }
 
 static void mk_player_set_on_event(mk_player ctx, on_mk_play_event cb, void *user_data, int type) {
-    assert(ctx && cb);
+    assert(ctx);
     MediaPlayerForC &obj = **((MediaPlayerForC::Ptr *)ctx);
     obj.setOnEvent(cb,user_data, type);
 }
@@ -192,7 +192,7 @@ API_EXPORT void API_CALL mk_player_set_on_shutdown(mk_player ctx, on_mk_play_eve
 }
 
 API_EXPORT void API_CALL mk_player_set_on_data(mk_player ctx, on_mk_play_data cb, void *user_data) {
-    assert(ctx && cb);
+    assert(ctx);
     MediaPlayerForC &obj = **((MediaPlayerForC::Ptr *)ctx);
     obj.setOnData(cb,user_data);
 }