diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common.h b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common.h
@@ -796,7 +796,11 @@
   return "";
 }
 
+#if SANITIZER_APPLE
+const uptr kModuleUUIDSize = 16;
+#else
 const uptr kModuleUUIDSize = 32;
+#endif
 const uptr kMaxSegName = 16;
 
 // Represents a binary loaded into virtual memory (e.g. this can be an
diff --git a/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt b/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt
--- a/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt
+++ b/compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt
@@ -31,6 +31,7 @@
   sanitizer_list_test.cpp
   sanitizer_lzw_test.cpp
   sanitizer_mac_test.cpp
+  sanitizer_module_uuid_size.cpp
   sanitizer_mutex_test.cpp
   sanitizer_nolibc_test.cpp
   sanitizer_posix_test.cpp
diff --git a/compiler-rt/lib/sanitizer_common/tests/sanitizer_module_uuid_size.cpp b/compiler-rt/lib/sanitizer_common/tests/sanitizer_module_uuid_size.cpp
new file mode 100644
--- /dev/null
+++ b/compiler-rt/lib/sanitizer_common/tests/sanitizer_module_uuid_size.cpp
@@ -0,0 +1,10 @@
+#include "sanitizer_common/sanitizer_common.h"
+#include "gtest/gtest.h"
+
+TEST(ModuleUUID, kModuleUUIDSize) {
+#if SANITIZER_APPLE
+    EXPECT_EQ(__sanitizer::kModuleUUIDSize, 16ULL);
+#else
+    EXPECT_EQ(__sanitizer::kModuleUUIDSize, 32ULL);
+#endif
+}