diff --git a/qurator/sbb_textline_detector/ocrd-tool.json b/qurator/sbb_textline_detector/ocrd-tool.json
index b23e0fc..5663d84 100644
--- a/qurator/sbb_textline_detector/ocrd-tool.json
+++ b/qurator/sbb_textline_detector/ocrd-tool.json
@@ -16,7 +16,8 @@
       "parameters": {
         "model": {
           "type": "string",
-          "format": "file",
+          "format": "uri",
+          "content-type": "text/directory",
           "cacheable": true,
           "description": "Path to directory containing models to be used (See https://qurator-data.de/sbb_textline_detector/)"
         }