diff --git a/glib.spec.in b/glib.spec.in
index dd7a822f5..0649c1b37 100644
--- a/glib.spec.in
+++ b/glib.spec.in
@@ -1,6 +1,7 @@
 # Note that this is NOT a relocatable package
 %define ver      @VERSION@
-%define rel      1
+%define  RELEASE 1
+%define  rel     %{?CUSTOM_RELEASE} %{!?CUSTOM_RELEASE:%RELEASE}
 %define prefix   /usr
 
 Summary: Handy library of utility functions