diff --git a/.templates/99-custom_script.sh b/.templates/99-custom_script.sh
index 2f4b3311f..5ba4e28c9 100644
--- a/.templates/99-custom_script.sh
+++ b/.templates/99-custom_script.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/with-contenv bashio
+# shellcheck shell=bash
 
 CONFIGSOURCE=$(bashio::config "CONFIG_LOCATION")
 CONFIGSOURCE="$(dirname "${CONFIGSOURCE}")"