diff --git a/contrib/cirrus/runner.sh b/contrib/cirrus/runner.sh
index 2de0b2d6..64117eba 100755
--- a/contrib/cirrus/runner.sh
+++ b/contrib/cirrus/runner.sh
@@ -71,8 +71,8 @@ _run_setup() {
     # automation, but the sources are in different directories.  It's
     # possible for a mismatch to happen, but should (hopefully) be unlikely.
     # Double-check to make sure.
-    if ! fgrep -qx "ID=$OS_RELEASE_ID" $mnt/etc/os-release || \
-       ! fgrep -qx "VERSION_ID=$OS_RELEASE_VER" $mnt/etc/os-release; then
+    if ! grep -Fqx "ID=$OS_RELEASE_ID" $mnt/etc/os-release || \
+       ! grep -Fqx "VERSION_ID=$OS_RELEASE_VER" $mnt/etc/os-release; then
             die "Somehow $SKOPEO_CIDEV_CONTAINER_FQIN is not based on $OS_REL_VER."
     fi
     msg "Copying test binaries from $SKOPEO_CIDEV_CONTAINER_FQIN /usr/local/bin/"