1 files changed, 2 insertions, 0 deletions
diff --git a/synapse/api/urls.py b/synapse/api/urls.py
index e36aeef31f..6379c86dde 100644
--- a/synapse/api/urls.py
+++ b/synapse/api/urls.py
@@ -42,6 +42,8 @@ class ConsentURIBuilder:
         """
         if hs_config.form_secret is None:
             raise ConfigError("form_secret not set in config")
+        if hs_config.public_baseurl is None:
+            raise ConfigError("public_baseurl not set in config")
 
         self._hmac_secret = hs_config.form_secret.encode("utf-8")
         self._public_baseurl = hs_config.public_baseurl