diff --git a/providers/provider_default.go b/providers/provider_default.go
index dbd93c91..ca418b2d 100644
--- a/providers/provider_default.go
+++ b/providers/provider_default.go
@@ -9,6 +9,7 @@ import (
 
 	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/apis/middleware"
 	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/apis/sessions"
+	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/logger"
 	"github.com/oauth2-proxy/oauth2-proxy/v7/pkg/requests"
 )
 
@@ -132,6 +133,8 @@ func (p *ProviderData) Authorize(_ context.Context, s *sessions.SessionState) (b
 		}
 	}
 
+	logger.Println("session groups do not match any allowed groups")
+
 	return false, nil
 }