diff --git a/compiler-rt/lib/scudo/standalone/memtag.h b/compiler-rt/lib/scudo/standalone/memtag.h
--- a/compiler-rt/lib/scudo/standalone/memtag.h
+++ b/compiler-rt/lib/scudo/standalone/memtag.h
@@ -52,6 +52,8 @@
 
 #if defined(__aarch64__)
 
+#if SCUDO_LINUX
+
 inline bool systemSupportsMemoryTagging() {
 #ifndef HWCAP2_MTE
 #define HWCAP2_MTE (1 << 18)
@@ -77,6 +79,14 @@
           PR_MTE_TCF_MASK) != PR_MTE_TCF_NONE;
 }
 
+#else // !SCUDO_LINUX
+
+inline bool systemSupportsMemoryTagging() { return false; }
+
+inline bool systemDetectsMemoryTagFaultsTestOnly() { return false; }
+
+#endif // SCUDO_LINUX
+
 inline void disableMemoryTagChecksTestOnly() {
   __asm__ __volatile__(".arch_extension mte; msr tco, #1");
 }