diff --git a/internal/server/server.go b/internal/server/server.go
index 427831d..4380a35 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -26,8 +26,8 @@ type Server struct {
 	CustomNotFoundStatusCode int
 
 	// Basic auth settings
-	Username string `flagName:"username" validate:"omitempty,alphanum,excluded_with=JWTSigningKey"`
-	Password string `flagName:"password" validate:"omitempty,alphanum,excluded_with=JWTSigningKey"`
+	Username string `flagName:"username" validate:"omitempty,excluded_with=JWTSigningKey"`
+	Password string `flagName:"password" validate:"omitempty,excluded_with=JWTSigningKey"`
 
 	// Boolean specific settings
 	CorsEnabled         bool