diff --git a/compose.yml b/compose.yml
index 4267f1d..1015fce 100644
--- a/compose.yml
+++ b/compose.yml
@@ -66,7 +66,7 @@ services:
     networks:
       - fogtype
   maddy:
-    image: foxcpp/maddy:0.6.3
+    image: foxcpp/maddy:0.6.3@sha256:616288f54b7a8328135b093c27d46d14fab4f3650753d9ea853262bf4e5f6eef
     restart: unless-stopped
     ports:
       - "25:25"