diff --git a/ggml-quants.c b/ggml-quants.c
index 14c113ce3..0a4b7dcf5 100644
--- a/ggml-quants.c
+++ b/ggml-quants.c
@@ -9333,8 +9333,8 @@ void ggml_vec_dot_iq1_s_q8_K  (int n, float * GGML_RESTRICT s, size_t bs, const
             const __m128i ql = _mm_loadu_si128((const __m128i*)qs); qs += 16;
             memcpy(&aux64, sc, 8); sc += 8;
             const __m128i qh = _mm_shuffle_epi8(_mm_set_epi64x(aux64 >> 4, aux64), shuffle_h);
-            const __m256i hbit = _mm256_cvtepi8_epi16(_mm_and_si128(qh, m8));
-            v_gindex = _mm256_or_si256(_mm256_cvtepi8_epi16(ql), _mm256_slli_epi16(hbit, 5));
+            const __m256i hbit = _mm256_cvtepu8_epi16(_mm_and_si128(qh, m8));
+            v_gindex = _mm256_or_si256(_mm256_cvtepu8_epi16(ql), _mm256_slli_epi16(hbit, 5));
             const __m128i scales = _mm_or_si128(_mm_slli_epi16(_mm_and_si128(qh, m7), 1), m1);
 
             for (int i32 = 0; i32 < 4; ++i32) {