diff --git a/third_party/llamafile/iqk_mul_mat.inc b/third_party/llamafile/iqk_mul_mat.inc
index e5ee4ed..228e7b1 100644
--- a/third_party/llamafile/iqk_mul_mat.inc
+++ b/third_party/llamafile/iqk_mul_mat.inc
@@ -2388,7 +2388,7 @@ struct SimpleBits {
 
 
 struct EvenSignHelper {
-    #ifdef HAVE_FANCY_SIMD
+    #ifdef HAVE_FANCY_SIMD && __AVX512VPOPCNTDQ__
         union sbits_t {
             __m128i vec;
             __mmask32 mask[4];