--- a/make/CreateJmods.gmk	Fri Mar 01 11:32:38 2019 +0100
+++ b/make/CreateJmods.gmk	Fri Mar 01 11:40:46 2019 +0100
@@ -120,7 +120,7 @@
     endif
   endif
 else # not java.base
-  ifeq ($(OPENJDK_TARGET_OS), windows)
+  ifeq ($(call isTargetOs, windows), true)
     # Only java.base needs to include the MSVC*_DLLs. Make sure no other module
     # tries to include them (typically imported ones).
     ifneq ($(MSVCR_DLL), )