diff --git a/doc/docker.md b/doc/docker.md
index e45a1fbb3..72980701a 100644
--- a/doc/docker.md
+++ b/doc/docker.md
@@ -73,6 +73,7 @@ Available options:
 * `ADMIN_PASSWORD`: the password for the `admin` user (leave unspecified if you do not want to create it)
 * `USER_PASSWORD`: the password for the first user `user` (leave unspecified if you do not want to create it)
 * `TRUST_PROXY`: set to `true` if you are using a reverse proxy in front of Etherpad (for example: Traefik for SSL termination via Let's Encrypt). This will affect security and correctness of the logs if not done
+* `IMPORT_MAX_FILE_SIZE`: maximum allowed file size when importing a pad, in bytes. Default: 52428800 (50 MB)
 * `LOGLEVEL`: valid values are `DEBUG`, `INFO`, `WARN` and `ERROR`
 
 ### Examples
diff --git a/settings.json.docker b/settings.json.docker
index 56677274f..c4dcc78ea 100644
--- a/settings.json.docker
+++ b/settings.json.docker
@@ -414,7 +414,7 @@
    *
    * File size is specified in bytes. Default is 50 MB.
    */
-  "importMaxFileSize": 52428800, // 50 * 1024 * 1024
+  "importMaxFileSize": "${IMPORT_MAX_FILE_SIZE:52428800}", // 50 * 1024 * 1024
 
   /*
    * Toolbar buttons configuration.