diff --git a/Makefile b/Makefile
index 86a27e3..d36b2f7 100644
--- a/Makefile
+++ b/Makefile
@@ -82,5 +82,5 @@ web: $(BALL_TAR_GZ) CHECKSUM.MD5
 	tar cf - javadoc | tar -C $(WEBDIR) -xvf -
 
 CHECKSUM.MD5: $(BALL_TAR_GZ) $(JARFILE)
-	md5 legacy/UMLGraph-2.10.* legacy/UMLGraph-4.8.* UMLGraph-$(VERSION).* >CHECKSUM.MD5
-	(cd lib ; md5 UmlGraph.jar) >>CHECKSUM.MD5
+	openssl md5 legacy/UMLGraph-2.10.* legacy/UMLGraph-4.8.* UMLGraph-$(VERSION).* >CHECKSUM.MD5
+	(cd lib ; openssl md5 UmlGraph.jar) >>CHECKSUM.MD5