diff --git a/src/idpyoidc/message/oidc/__init__.py b/src/idpyoidc/message/oidc/__init__.py
index da8cd844..2b590c65 100644
--- a/src/idpyoidc/message/oidc/__init__.py
+++ b/src/idpyoidc/message/oidc/__init__.py
@@ -945,7 +945,7 @@ def verify(self, **kwargs):
         # Check that any alg that is not "none" is supported.
         # While OpenID Connect Core 1.0 says RS256 MUST be supported,
         # reality has moved on and more modern alg values may be required.
-        if not any(lower(i) == "none" for i in self["id_token_signing_alg_values_supported"]:
+        if not any(i.lower == "none" for i in self["id_token_signing_alg_values_supported"]):
             raise ValueError("Secure signing algorithm (for example RS256 or ES256) missing from id_token_signing_alg_values_supported")
 
         if not parts.query and not parts.fragment: