diff --git a/oidc_provider/lib/endpoints/authorize.py b/oidc_provider/lib/endpoints/authorize.py
index 6972728..0ae86d9 100644
--- a/oidc_provider/lib/endpoints/authorize.py
+++ b/oidc_provider/lib/endpoints/authorize.py
@@ -82,8 +82,6 @@ class AuthorizeEndpoint(object):
 
     def create_response_uri(self):
         try:
-            self.validate_params()
-
             if self.grant_type == 'authorization_code':
                 code = create_code(
                     user=self.request.user,
@@ -95,7 +93,7 @@ class AuthorizeEndpoint(object):
                 # Create the response uri.
                 uri = self.params.redirect_uri + '?code={0}'.format(code.code)
 
-            else:  # Implicit Flow
+            elif self.grant_type == 'implicit':
                 id_token_dic = create_id_token(
                     user=self.request.user,
                     aud=self.client.client_id)
diff --git a/oidc_provider/views.py b/oidc_provider/views.py
index b214c57..85f783f 100644
--- a/oidc_provider/views.py
+++ b/oidc_provider/views.py
@@ -73,6 +73,8 @@ class AuthorizeView(View):
         allow = True if request.POST.get('allow') else False
 
         try:
+            authorize.validate_params()
+            
             if not allow:
                 raise AuthorizeError(authorize.params.redirect_uri,
                                      'access_denied',