diff --git a/docker-compose.yml b/docker-compose.yml
index 164362e..34f56da 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -37,7 +37,7 @@ services:
       - PMA_HOST=db
       - PMA_USER=root
       - PMA_PASSWORD=secret
-      - UPLOAD_LIMIT: 300M
+      - UPLOAD_LIMIT=300M
     depends_on:
       - db
 volumes: