diff --git a/jupyter/base/values/values.yaml b/jupyter/base/values/values.yaml
index b9848b6..8acd5b8 100644
--- a/jupyter/base/values/values.yaml
+++ b/jupyter/base/values/values.yaml
@@ -25,7 +25,7 @@ hub:
         data = {
           'grant_type': refresh_token,
           'code': code,
-          'refresh_token: refresh_token,
+          'refresh_token': refresh_token,
           'client_id': client_id,
           'client_secret': client_secret
         }