diff --git a/internal/core/src/common/Schema.h b/internal/core/src/common/Schema.h
index 9220887263..725b37db70 100644
--- a/internal/core/src/common/Schema.h
+++ b/internal/core/src/common/Schema.h
@@ -173,6 +173,5 @@ class Schema {
 };
 
 using SchemaPtr = std::shared_ptr<Schema>;
-using idx_t = int64_t;
 
 }  // namespace milvus