diff --git a/files/initrd/opt/arc/init.sh b/files/initrd/opt/arc/init.sh
index 0fb52273..8b8308ad 100755
--- a/files/initrd/opt/arc/init.sh
+++ b/files/initrd/opt/arc/init.sh
@@ -82,7 +82,7 @@ if grep -q "automated_arc" /proc/cmdline; then
 else
   writeConfigKey "automated" "false" "${USER_CONFIG_FILE}"
 fi
-[ echo "${ARC_VERSION}" | grep -q "s" ] && writeConfigKey "arc.branch" "s" "${USER_CONFIG_FILE}" || writeConfigKey "arc.branch" "x" "${USER_CONFIG_FILE}"
+[[ echo "${ARC_VERSION}" | grep -q "s" ]] && writeConfigKey "arc.branch" "s" "${USER_CONFIG_FILE}" || writeConfigKey "arc.branch" "x" "${USER_CONFIG_FILE}"
 [ -f "${PART3_PATH}/automated" ] && rm -f "${PART3_PATH}/automated" >/dev/null
 # Check for compatibility
 compatboot