diff --git a/configure.ac b/configure.ac
index 38b099b0..beff7faf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 dnl Process this file with autoconf to produce a configure script.
 
 AC_PREREQ(2.61)
-AC_INIT(metaphysicl, 0.4.0, roystgnr@ices.utexas.edu)
+AC_INIT(metaphysicl, 0.5.0, roystgnr@ices.utexas.edu)
 AC_CONFIG_MACRO_DIR([m4])
 
 AC_CONFIG_HEADER(metaphysicl_config.h.tmp)