diff --git a/setup-nasbeery b/setup-nasbeery
index c985a5d..970e690 100644
--- a/setup-nasbeery
+++ b/setup-nasbeery
@@ -76,9 +76,8 @@ FORMAT=$?
 #Pin-Priority: 900
 #EOF
 
-grep contrib /etc/apt/sources.list
-if [ $? -gt 0 ]; then
-  sed -i "s/main/main contrib non-free/g" /etc/apt/sources.list
+if ! grep -q "contrib" /etc/apt/sources.list; then
+  sed -i 's/ main non-free-firmware$/ main contrib non-free-firmware/' /etc/apt/sources.list
 fi
 
 #echo "Add debian bullseye backports repo"