--- a/make/lib/CoreLibraries.gmk	Tue May 22 10:08:04 2018 -0700
+++ b/make/lib/CoreLibraries.gmk	Tue May 22 11:04:36 2018 -0700
@@ -188,7 +188,6 @@
         -I$(TOPDIR)/src/java.base/$(OPENJDK_TARGET_OS_TYPE)/native/libjava \
         -I$(SUPPORT_OUTPUTDIR)/headers/java.base, \
     CFLAGS_unix := $(BUILD_LIBZIP_MMAP) -UDEBUG, \
-    DISABLED_WARNINGS_gcc := implicit-fallthrough, \
     LDFLAGS := $(LDFLAGS_JDKLIB) \
         $(call SET_SHARED_LIBRARY_ORIGIN), \
     LIBS_unix := -ljvm -ljava $(LIBZ_LIBS), \