diff --git a/src/generator/main.py b/src/generator/main.py
index 18c214f..670644e 100644
--- a/src/generator/main.py
+++ b/src/generator/main.py
@@ -21,6 +21,9 @@ def generate(schema, schema_dir, all, output_dir, language: Optional[str] = None
     if schema is None and not all:
         error("Please pass option --all or argument schema")
         return
+    if schema is not None and all:
+        error("Dont use schema with --all. use one of them.")
+        return
     if language:
         generator_cls = language_registry.get(language)
         if generator_cls is None: