diff --git a/docker/deploy.sh b/docker/deploy.sh
index 084e1fcb..92ef537a 100755
--- a/docker/deploy.sh
+++ b/docker/deploy.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-mkdocs_simple_gen --config-file ${ {$INPUT_CONFIG} : 'mkdocs.yml' }
+mkdocs_simple_gen --config-file ${INPUT_CONFIG:-'mkdocs.yml'}
 mkdocs build
 
 git config --global user.name "${GITHUB_ACTOR}"