diff --git a/roles/lib/install-docker.yml b/roles/lib/install-docker.yml
index 8c03341..71d8e71 100644
--- a/roles/lib/install-docker.yml
+++ b/roles/lib/install-docker.yml
@@ -32,7 +32,7 @@
       uris: "https://download.docker.com/linux/debian"
       components: [stable]
       suites: ["trixie"]
-      signed_by: https://download.docker.com/linux/debian/gpg
+      signed_by: "https://download.docker.com/linux/debian/gpg"
       state: present
       enabled: true
     when: