diff --git a/config/prod.js b/config/prod.js
index b525df9..07755aa 100644
--- a/config/prod.js
+++ b/config/prod.js
@@ -12,6 +12,7 @@ module.exports = {
         scopes: process.env.OIDC_AVAILABLE_SCOPES,
         grantTypes: process.env.OIDC_GRANT_TYPES,
         signedResponseAlg: process.env.OIDC_ID_TOKEN_SIGNED_RESPONSE_ALG,
+        codeChallengeMethod: 'S256',
         responseTypes: process.env.OIDC_RESPONSE_TYPES,
         authMethod: process.env.OIDC_TOKEN_ENDPOINT_AUTH_METHOD,
     },
diff --git a/src/services/auth-oidc/auth-oidc.class.ts b/src/services/auth-oidc/auth-oidc.class.ts
index f7bcc90..668ac44 100644
--- a/src/services/auth-oidc/auth-oidc.class.ts
+++ b/src/services/auth-oidc/auth-oidc.class.ts
@@ -39,7 +39,7 @@ export class AuthOidcService<ServiceParams extends AuthOidcParams = AuthOidcPara
             scope: config.get('oidc.scopes'),
             response_type: config.get('oidc.responseTypes'),
             code_challenge: codeChallenge,
-            code_challenge_method: config.get('oidc.signedResponseAlg'),
+            code_challenge_method: config.get('oidc.codeChallengeMethod'),
         });
 
         params.session.codeVerifier = codeVerifier;