diff --git a/compiler-rt/lib/hwasan/hwasan_allocator.cpp b/compiler-rt/lib/hwasan/hwasan_allocator.cpp
--- a/compiler-rt/lib/hwasan/hwasan_allocator.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_allocator.cpp
@@ -41,6 +41,10 @@
 // Initialized in HwasanAllocatorInit, an never changed.
 static ALIGNED(16) u8 tail_magic[kShadowAlignment - 1];
 
+#if defined(HWASAN_ALIASING_MODE)
+uptr kAliasRegionStart;  // Always 0 when aliases aren't used.
+#endif
+
 bool HwasanChunkView::IsAllocated() const {
   return metadata_ && metadata_->alloc_context_id &&
          metadata_->get_requested_size();
@@ -85,7 +89,7 @@
                        !flags()->disable_allocator_tagging);
   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
   allocator.Init(common_flags()->allocator_release_to_os_interval_ms,
-                 kAliasRegionStart);
+                 GetAliasRegionStart());
   for (uptr i = 0; i < sizeof(tail_magic); i++)
     tail_magic[i] = GetCurrentThread()->GenerateRandomTag();
 }
diff --git a/compiler-rt/lib/hwasan/hwasan_linux.cpp b/compiler-rt/lib/hwasan/hwasan_linux.cpp
--- a/compiler-rt/lib/hwasan/hwasan_linux.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_linux.cpp
@@ -76,8 +76,6 @@
 uptr kHighMemStart;
 uptr kHighMemEnd;
 
-uptr kAliasRegionStart;  // Always 0 when aliases aren't used.
-
 static void PrintRange(uptr start, uptr end, const char *name) {
   Printf("|| [%p, %p] || %.*s ||\n", (void *)start, (void *)end, 10, name);
 }
diff --git a/compiler-rt/lib/hwasan/hwasan_mapping.h b/compiler-rt/lib/hwasan/hwasan_mapping.h
--- a/compiler-rt/lib/hwasan/hwasan_mapping.h
+++ b/compiler-rt/lib/hwasan/hwasan_mapping.h
@@ -48,7 +48,9 @@
 extern uptr kHighMemStart;
 extern uptr kHighMemEnd;
 
+#if defined(HWASAN_ALIASING_MODE)
 extern uptr kAliasRegionStart;
+#endif
 
 inline uptr GetShadowOffset() {
   return SANITIZER_FUCHSIA ? 0 : __hwasan_shadow_memory_dynamic_address;
@@ -70,6 +72,14 @@
          (kHighShadowStart <= p && p <= kHighShadowEnd);
 }
 
+static inline uptr GetAliasRegionStart() {
+#if defined(HWASAN_ALIASING_MODE)
+  return kAliasRegionStart;
+#else
+  return 0;
+#endif
+}
+
 }  // namespace __hwasan
 
 #endif  // HWASAN_MAPPING_H