diff --git a/configure.in b/configure.in
index 7f67f93d8..eaf38fa8b 100644
--- a/configure.in
+++ b/configure.in
@@ -7,7 +7,7 @@ m4_define([metacity_minor_version], [25])
 m4_define([metacity_micro_version], [55])
 m4_define([mutter_version],[0.1])
 m4_define([metacity_version],
-          [metacity_major_version.metacity_minor_version.metacity_micro_version-mutter_version])
+          [metacity_major_version.metacity_minor_version.metacity_micro_version~mutter_version])
 
 m4_define([metacity_clutter_plugin_api_version], [2])