diff --git a/ec2-create-ce b/ec2-create-ce
index 1a70e02..43fcb37 100755
--- a/ec2-create-ce
+++ b/ec2-create-ce
@@ -454,7 +454,7 @@ if [ -f /etc/apt/sources.list.d/backports.list ] && grep -q 'jessie-backports' /
 fi
 
 # workaround for mr13.2.1 and newer with bookworm-backports enabled by default:
-if [ -f /etc/apt/sources.list.d/debian.sources ] && grep -q '-backports' /etc/apt/sources.list.d/debian.sources ; then
+if [ -f /etc/apt/sources.list.d/debian.sources ] && grep -q -- '-backports' /etc/apt/sources.list.d/debian.sources ; then
   echo "backports is unexpected, disabling from /etc/apt/sources.list.d/debian.sources"
   sed -i -E 's/ [a-z]+-backports//' /etc/apt/sources.list.d/debian.sources
 fi