diff --git a/ggml/src/ggml-cpu/arch/x86/quants.c b/ggml/src/ggml-cpu/arch/x86/quants.c
index 74d699f63..78055a60e 100644
--- a/ggml/src/ggml-cpu/arch/x86/quants.c
+++ b/ggml/src/ggml-cpu/arch/x86/quants.c
@@ -3329,7 +3329,8 @@ void ggml_vec_dot_iq1_s_q8_K(int n, float * GGML_RESTRICT s, size_t bs, const vo
         __m256i sumi = _mm256_setzero_si256();
         int sumi1 = 0;
         for (int ib = 0; ib < QK_K/32; ib += 2) {
-#ifdef __BMI2__
+// _pdep_u64 is only available on x86_64 (64-bit); use scalar fallback on 32-bit
+#if defined(__BMI2__) && defined(__x86_64__)
             const uint64_t packed_idx1 = _pdep_u64(*(const uint32_t *)qs, 0x00ff00ff00ff00ffULL) | _pdep_u64(qh[ib], 0x700070007000700ULL);
             const uint64_t packed_idx2 = _pdep_u64(*(const uint32_t *)(qs + 4), 0x00ff00ff00ff00ffULL) | _pdep_u64(qh[ib + 1], 0x700070007000700ULL);
             const uint16_t *idx1 = (const uint16_t *)(&packed_idx1);
@@ -3468,7 +3469,8 @@ void ggml_vec_dot_iq1_m_q8_K(int n, float * GGML_RESTRICT s, size_t bs, const vo
         __m256i sumi1 = _mm256_setzero_si256();
         __m256i sumi2 = _mm256_setzero_si256();
         for (int ib = 0; ib < QK_K/32; ib += 2) {
-#ifdef __BMI2__
+// _pdep_u64 is only available on x86_64 (64-bit); use scalar fallback on 32-bit
+#if defined(__BMI2__) && defined(__x86_64__)
             const uint64_t packed_idx1 = _pdep_u64(*(const uint32_t *)qs, 0x00ff00ff00ff00ffULL)
                                        | _pdep_u64(*(const uint16_t*)(qh) & 0x7777, 0xf000f000f000f00ULL);
             const uint64_t packed_idx2 = _pdep_u64(*(const uint32_t *)(qs + 4), 0x00ff00ff00ff00ffULL)