diff -r e30211561a17 -r 48ff68e2fe5c make/TestImage.gmk
--- a/make/TestImage.gmk	Thu Feb 07 10:26:32 2019 +0100
+++ b/make/TestImage.gmk	Thu Feb 07 12:35:45 2019 +0100
@@ -30,7 +30,7 @@
 
 ############################################################################
 
-ifeq ($(OPENJDK_TARGET_OS), windows)
+ifeq ($(call isTargetOs, windows), true)
   FIXPATH_COPY := $(TEST_IMAGE_DIR)/bin/fixpath.exe
 
   $(FIXPATH_COPY): $(firstword $(FIXPATH))