diff --git a/kitty/simd-string.c b/kitty/simd-string.c
index 4d63e9fde..61b391fd5 100644
--- a/kitty/simd-string.c
+++ b/kitty/simd-string.c
@@ -119,12 +119,13 @@ init_simd(void *x) {
     PyObject *module = (PyObject*)x;
     if (PyModule_AddFunctions(module, module_methods) != 0) return false;
 #define A(x, val) { Py_INCREF(Py_##val); if (0 != PyModule_AddObject(module, #x, Py_##val)) return false; }
+#define do_check() has_sse4_2 = __builtin_cpu_supports("sse4.2") != 0; has_avx2 = __builtin_cpu_supports("avx2") != 0;
 #ifdef __APPLE__
 #ifdef __arm64__
     // simde takes care of NEON on Apple Silicon
     has_sse4_2 = true; has_avx2 = true;
 #else
-    has_sse4_2 = __builtin_cpu_supports("sse4.2") != 0; has_avx2 = __builtin_cpu_supports("avx2") != 0;
+    do_check();
 #endif
 #else
 #ifdef __aarch64__
@@ -132,9 +133,10 @@ init_simd(void *x) {
     // basic AVX2 and SSE4.2 intrinsics, so hopefully they work on ARM
     has_sse4_2 = true; has_avx2 = true;
 #else
-    has_sse4_2 = __builtin_cpu_supports("sse4.2") != 0; has_avx2 = __builtin_cpu_supports("avx2") != 0;
+    do_check();
 #endif
 #endif
+#undef do_check
     if (has_avx2) {
         A(has_avx2, True);
         find_either_of_two_bytes_impl = find_either_of_two_bytes_256;