diff --git a/changelog.d/8252.feature b/changelog.d/8252.feature
new file mode 100644
index 000000000000..7e69b7242943
--- /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 036f8c0e9090..cc7401888b24 100644
--- a/synapse/config/saml2_config.py
+++ b/synapse/config/saml2_config.py
@@ -171,7 +171,7 @@ def read_config(self, config, **kwargs):
 
         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