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 3dcf74b12..1d66a4183 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
@@ -17,6 +17,7 @@ package main
 import (
 	"net/http"
 	"os"
+	"strconv"
 
 	"github.com/matrix-org/dendrite/common"
 	"github.com/matrix-org/dendrite/mediaapi/config"
@@ -48,11 +49,16 @@ func main() {
 	if serverName == "" {
 		serverName = "localhost"
 	}
+	maxFileSizeBytes, err := strconv.ParseInt(os.Getenv("MAX_FILE_SIZE_BYTES"), 10, 64)
+	if err != nil {
+		maxFileSizeBytes = 10 * 1024 * 1024
+		log.Info("Failed to parse MAX_FILE_SIZE_BYTES. Defaulting to %v bytes.", maxFileSizeBytes)
+	}
 
 	cfg := &config.MediaAPI{
 		ServerName:       types.ServerName(serverName),
 		BasePath:         types.Path(basePath),
-		MaxFileSizeBytes: 10 * 1024 * 1024,
+		MaxFileSizeBytes: types.ContentLength(maxFileSizeBytes),
 		DataSource:       dataSource,
 	}