--- a/make/RunTestsPrebuiltSpec.gmk	Sat Oct 13 19:28:10 2018 +0200
+++ b/make/RunTestsPrebuiltSpec.gmk	Mon Oct 15 11:39:10 2018 -0700
@@ -124,7 +124,7 @@
 JMOD := $(FIXPATH) $(JMOD_CMD)
 JARSIGNER := $(FIXPATH) $(JARSIGNER_CMD)
 
-BUILD_JAVA := $(JAVA)
+BUILD_JAVA := $(JDK_IMAGE_DIR)/bin/JAVA
 ################################################################################
 # Some common tools. Assume most common name and no path.
 AWK := awk