diff --git a/trader.spec b/trader.spec
index 41a8d86..9312517 100644
--- a/trader.spec
+++ b/trader.spec
@@ -17,7 +17,7 @@
 
 Name:           trader
 
-%if ! %{is_prerelease}
+%if ! 0%{?is_prerelease}
 Version:        %{real_version}
 Source0:        ftp://ftp.zap.org.au/pub/trader/unix/trader-%{version}.tar.bz2
 %else