diff --git a/catatonit.spec b/catatonit.spec
index 3ff3afd..b65195f 100644
--- a/catatonit.spec
+++ b/catatonit.spec
@@ -1,9 +1,9 @@
 %global built_tag v0.1.7
-%global built_tag_strip 0.1.7
+%global built_tag_strip %(b=%{built_tag}; echo ${b:1})
 %global gen_version %(b=%{built_tag_strip}; echo ${b/-/"~"})
 
 Name: catatonit
-Version: 0.1.7
+Version: %{gen_version}
 Summary: A signal-forwarding process manager for containers
 License: GPLv3+
 Release: %autorelease