diff --git a/byaccj.spec b/byaccj.spec
index d1511fa..7e1b0b3 100644
--- a/byaccj.spec
+++ b/byaccj.spec
@@ -54,7 +54,7 @@ Java now!
 %prep
 %setup -q -n %{name}%{version}
 
-sed -i -e 's|-arch i386||g' src/Makefile
+sed -i -e 's|-arch i386 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -mmacosx-version-min=10.4||g' src/Makefile
 
 %build
 pushd src