diff --git a/src/github.com/matrix-org/dendrite/cmd/dendrite-media-api-server/main.go b/src/github.com/matrix-org/dendrite/cmd/dendrite-media-api-server/main.go
index d7191508a..b053076a2 100644
--- a/src/github.com/matrix-org/dendrite/cmd/dendrite-media-api-server/main.go
+++ b/src/github.com/matrix-org/dendrite/cmd/dendrite-media-api-server/main.go
@@ -31,11 +31,12 @@ import (
 )
 
 var (
-	bindAddr               = os.Getenv("BIND_ADDRESS")
-	dataSource             = os.Getenv("DATABASE")
-	logDir                 = os.Getenv("LOG_DIR")
-	serverName             = os.Getenv("SERVER_NAME")
-	basePath               = os.Getenv("BASE_PATH")
+	bindAddr   = os.Getenv("BIND_ADDRESS")
+	dataSource = os.Getenv("DATABASE")
+	logDir     = os.Getenv("LOG_DIR")
+	serverName = os.Getenv("SERVER_NAME")
+	basePath   = os.Getenv("BASE_PATH")
+	// Note: if the MAX_FILE_SIZE_BYTES is set to 0, it will be unlimited
 	maxFileSizeBytesString = os.Getenv("MAX_FILE_SIZE_BYTES")
 )
 
diff --git a/src/github.com/matrix-org/dendrite/mediaapi/config/config.go b/src/github.com/matrix-org/dendrite/mediaapi/config/config.go
index c7346d313..6163f2315 100644
--- a/src/github.com/matrix-org/dendrite/mediaapi/config/config.go
+++ b/src/github.com/matrix-org/dendrite/mediaapi/config/config.go
@@ -27,6 +27,7 @@ type MediaAPI struct {
 	AbsBasePath types.Path `yaml:"abs_base_path"`
 	// The maximum file size in bytes that is allowed to be stored on this server.
 	// Note that remote files larger than this can still be proxied to a client, they will just not be cached.
+	// Note: if MaxFileSizeBytes is set to 0, the size is unlimited.
 	MaxFileSizeBytes types.ContentLength `yaml:"max_file_size_bytes"`
 	// The postgres connection config for connecting to the database e.g a postgres:// URI
 	DataSource string `yaml:"database"`