diff --git a/sbn_survey_image_service/app.py b/sbn_survey_image_service/app.py
index a349cb7..ef96f17 100755
--- a/sbn_survey_image_service/app.py
+++ b/sbn_survey_image_service/app.py
@@ -30,7 +30,7 @@
 app.add_api(
     "openapi.yaml",
     arguments={
-        "version": version,
+        "version": str(version),
         "base_href": ENV.BASE_HREF,
     },
 )