diff --git a/changelog.d/8252.feature b/changelog.d/8252.feature
new file mode 100644
index 0000000000..7e69b72429
--- /dev/null
+++ b/changelog.d/8252.feature
@@ -0,0 +1 @@
+Use the default template file when its equivalent is not found in a custom template directory.
diff --git a/synapse/config/saml2_config.py b/synapse/config/saml2_config.py
index 036f8c0e90..cc7401888b 100644
--- a/synapse/config/saml2_config.py
+++ b/synapse/config/saml2_config.py
@@ -171,7 +171,7 @@ class SAML2Config(Config):
 
         self.saml2_error_html_template = self.read_templates(
             ["saml_error.html"], saml2_config.get("template_dir")
-        )
+        )[0]
 
     def _default_saml_config_dict(
         self, required_attributes: set, optional_attributes: set