--- a/make/modules/java.desktop/lib/ClientLibraries.gmk
+++ b/make/modules/java.desktop/lib/ClientLibraries.gmk
@@ -281,6 +281,7 @@ endif
 ifeq ($(USE_EXTERNAL_HARFBUZZ), true)
    LIBFONTMANAGER_EXTRA_SRC =
    LIBFONTMANAGER_LIBS += $(HARFBUZZ_LIBS)
+   LIBFONTMANAGER_CFLAGS += $(HARFBUZZ_CFLAGS)
 else
    LIBFONTMANAGER_EXTRA_SRC = libharfbuzz