diff --git a/sendmail.spec b/sendmail.spec
index 46b2920..01b086c 100644
--- a/sendmail.spec
+++ b/sendmail.spec
@@ -264,7 +264,7 @@ Make() {
 		MSPQOWN=${nameuser}
 }
 
-OBJDIR=obj.$(uname -s).$(uname -r).%(arch)
+OBJDIR=obj.$(uname -s).$(uname -r).%{_arch}
 
 Make install -C $OBJDIR/libmilter
 Make install -C $OBJDIR/libsmutil