--- a/make/ModuleWrapper.gmk	Tue Feb 05 10:24:39 2019 +0100
+++ b/make/ModuleWrapper.gmk	Tue Feb 05 14:57:24 2019 +0100
@@ -42,7 +42,7 @@
 include $(MAKEFILE_PREFIX)-$(MODULE).gmk
 
 # Setup copy rules from the modules directories to the jdk image directory.
-ifeq ($(OPENJDK_TARGET_OS), windows)
+ifeq ($(call isTargetOs, windows), true)
   TO_BIN_FILTER := %$(SHARED_LIBRARY_SUFFIX) %.diz %.pdb %.map
 
   $(eval $(call SetupCopyFiles, COPY_LIBS_TO_BIN, \