diff --git a/Dockerfile b/Dockerfile
index 3395cca..6d561b1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,3 +1,4 @@
+ARG AKKOMA_COMMIT
 FROM registry.nrd.li/nrdli/akkoma-base:${AKKOMA_COMMIT}
 
 ENV PROD_SECRET_FILE=/config/prod.secret.exs