$OpenBSD$
--- make/makefile.ver.orig	Thu Apr 29 21:23:31 2010
+++ make/makefile.ver	Thu Apr 29 21:25:17 2010
@@ -1,4 +1,4 @@
 # Shared library versions for Unix
-shared_version = 0.4.3
-shared_major_minor = 0.4
-shared_major = 0
+shared_version ?= 0.4.3
+shared_major_minor ?= 0.4
+shared_major ?= 0