--- orc/orcprogram-x86.c.orig	2026-08-11 17:29:40.000000000 -0600
+++ orc/orcprogram-x86.c	2026-08-11 21:33:42.000000000 -0600
@@ -13,8 +13,12 @@
 #include <orc/orcinternal.h>
 
 #if defined(__APPLE__)
+#include <AvailabilityMacros.h>
+// Not available in Tiger.
+#if MAC_OS_X_VERSION_MIN_REQUIRED > 1040
 #include  <libkern/OSCacheControl.h>
 #endif
+#endif
 
 #if defined(_WIN32)
 #include <windows.h>
@@ -1219,8 +1223,21 @@
 orc_x86_flush_cache (OrcCode *code)
 {
 #if defined(__APPLE__)
+// https://gcc.gnu.org/onlinedocs/gcc-4.2.3/gcc/X86-Built_002din-Functions.html
+// https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/sys_dcache_flush.3.html
+// sys_icache_invalidate and sys_dcache_flush were introduced in Mac OS X 10.5.
+// On Intel, sys_icace_invalidate is a no-op. GCC builtin can be used for dcache.
+// However GCC builtin only does 64 bytes. We need to do it for code->code_size.
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1050
+    unsigned char *p = (unsigned char *)code->code;
+    size_t i;
+    for (i = 0; i < code->code_size; i += 64) {
+      __builtin_ia32_clflush(p + i);
+    }
+#else
   sys_dcache_flush(code->code, code->code_size);
   sys_icache_invalidate(code->exec, code->code_size);
+#endif
 #elif defined (_WIN32)
   HANDLE h_proc = GetCurrentProcess();