diff --git a/centos-mirror-tools/dl_rpms.sh b/centos-mirror-tools/dl_rpms.sh
index 67cf7924..5fd66eef 100755
--- a/centos-mirror-tools/dl_rpms.sh
+++ b/centos-mirror-tools/dl_rpms.sh
@@ -60,7 +60,7 @@ while getopts "c:nxh" o; do
         c)
             # Use an alternate yum.conf
             YUMCONFOPT="-c $OPTARG"
-            RELEASEVER="--$(grep releasever= ${OPTARG})"
+            grep -q "releasever=" $OPTARG && RELEASEVER="--$(grep releasever= ${OPTARG})"
             ;;
         h)
             # Help
diff --git a/centos-mirror-tools/mirror-check.sh b/centos-mirror-tools/mirror-check.sh
index 43a92a17..919cfb80 100755
--- a/centos-mirror-tools/mirror-check.sh
+++ b/centos-mirror-tools/mirror-check.sh
@@ -115,7 +115,7 @@ while getopts "c:" opt; do
     case $opt in
         c)
             extra_opts="-c ${OPTARG}"
-            RELEASEVER="--$(grep releasever= ${OPTARG})"
+            grep -q "releasever=" $OPTARG && RELEASEVER="--$(grep releasever= ${OPTARG})"
             ;;
         \?)
             echo "Invalid option: -$OPTARG" >&2