diff --git a/make/Jprt.gmk b/make/Jprt.gmk
index c1ebee5945..b833f8632f 100644
--- a/make/Jprt.gmk
+++ b/make/Jprt.gmk
@@ -25,6 +25,9 @@
 
 # This file is contains targets utilities needed by JPRT.
 
+          ifdef ALT_BSDIFF_DIR
+	    @$(ECHO) " --with-bsdiff-dir=$(call UnixPath,$(ALT_BSDIFF_DIR)) " >> $@.tmp
+          endif
 ifndef JPRT_ARCHIVE_BUNDLE
   JPRT_ARCHIVE_BUNDLE=/tmp/jprt_bundles/j2sdk-image.zip
 endif