diff --git a/src/layer/x86/lstm_int8.h b/src/layer/x86/lstm_int8.h
index 67a9b89570e..a289dcb99f7 100644
--- a/src/layer/x86/lstm_int8.h
+++ b/src/layer/x86/lstm_int8.h
@@ -1992,11 +1992,7 @@ static void lstm_int8(const Mat& bottom_blob_int8, const Mat& bottom_blob_int8_d
 
                 __m512i _hh_cont0 = _mm512_shuffle_epi32(_hh_cont, _MM_PERM_AAAA);
 
-#if __AVX512VNNI__
-                _lstm_IFOGh0 = _mm512_dpwssd_epi32(_lstm_IFOGh0, _ww, _hh_cont0);
-#else
                 _lstm_IFOGh0 = _mm512_add_epi32(_lstm_IFOGh0, _mm512_madd_epi16(_ww, _hh_cont0));
-#endif // __AVX512VNNI__
 
                 kptr += 32;
             }