diff --git a/core/src/index/thirdparty/hnswlib/hnswlib.h b/core/src/index/thirdparty/hnswlib/hnswlib.h
index f394247369..89d8d423a7 100644
--- a/core/src/index/thirdparty/hnswlib/hnswlib.h
+++ b/core/src/index/thirdparty/hnswlib/hnswlib.h
@@ -23,6 +23,7 @@
 #endif
 #endif
 
+#include <fstream>
 #include <queue>
 #include <vector>