diff --git a/GNUmakefile b/GNUmakefile
index b9874f3666..951aa6849c 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -227,7 +227,7 @@ vm/ffi_test.o: vm/ffi_test.c
 	$(TOOLCHAIN_PREFIX)$(CC) -c $(CFLAGS) $(FFI_TEST_CFLAGS) -o $@ $<
 
 vm/master.hpp.gch: vm/master.hpp $(MASTER_HEADERS)
-	$(TOOLCHAIN_PREFIX)$(CXX) -c -x c++-header $(CFLAGS) -o $@ $<
+	$(TOOLCHAIN_PREFIX)$(CXX) -c -x c++-header $(CFLAGS) $(CXXFLAGS) -o $@ $<
 
 %.o: %.cpp vm/master.hpp.gch
 	$(TOOLCHAIN_PREFIX)$(CXX) -c $(CFLAGS) $(CXXFLAGS) -o $@ $<