--- old/make/CopyImportModules.gmk	2019-02-05 15:44:50.670734012 +0100
+++ new/make/CopyImportModules.gmk	2019-02-05 15:44:50.494734011 +0100
@@ -38,7 +38,7 @@
 $(eval $(call FillCacheFind, $(LIBS_DIR) $(CMDS_DIR) $(CONF_DIR)))
 
 ifneq ($(LIBS_DIR), )
-  ifeq ($(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, \