diff --git a/make/hotspot/gensrc/GensrcAdlc.gmk b/make/hotspot/gensrc/GensrcAdlc.gmk
index d25b517252f1..8f17b28911a2 100644
--- a/make/hotspot/gensrc/GensrcAdlc.gmk
+++ b/make/hotspot/gensrc/GensrcAdlc.gmk
@@ -99,6 +99,9 @@ ifeq ($(call check-jvm-feature, compiler2), true)
     ADLCFLAGS += -DAIX=1
   else ifeq ($(OPENJDK_TARGET_OS), macosx)
     ADLCFLAGS += -D_ALLBSD_SOURCE=1 -D_GNU_SOURCE=1
+    ifeq ($(HOTSPOT_TARGET_CPU_ARCH), aarch64)
+      ADLCFLAGS += -DR18_RESERVED=1
+    endif
   else ifeq ($(OPENJDK_TARGET_OS), windows)
     ifeq ($(call isTargetCpuBits, 64), true)
       ADLCFLAGS += -D_WIN64=1
diff --git a/src/hotspot/cpu/aarch64/globalDefinitions_aarch64.hpp b/src/hotspot/cpu/aarch64/globalDefinitions_aarch64.hpp
index 4f9c5207587b..83043feb5a2e 100644
--- a/src/hotspot/cpu/aarch64/globalDefinitions_aarch64.hpp
+++ b/src/hotspot/cpu/aarch64/globalDefinitions_aarch64.hpp
@@ -53,7 +53,7 @@ const bool CCallingConventionRequiresIntsAsLongs = false;
 
 #define THREAD_LOCAL_POLL
 
-#if defined(_WIN64)
+#if defined(__APPLE__) || defined(_WIN64)
 #define R18_RESERVED
 #define R18_RESERVED_ONLY(code) code
 #define NOT_R18_RESERVED(code)