diff --git a/c_api/index_io_c_ex.cpp b/c_api/index_io_c_ex.cpp
index adcbe77b32..0efe59eb95 100644
--- a/c_api/index_io_c_ex.cpp
+++ b/c_api/index_io_c_ex.cpp
@@ -40,3 +40,8 @@ int faiss_read_index_buf(const uint8_t* buf, size_t size, int io_flags, FaissInd
     }
     CATCH_AND_HANDLE
 }
+
+void faiss_free_buf(uint8_t** buf) {
+    free(*buf);
+    *buf = nullptr;
+}
diff --git a/c_api/index_io_c_ex.h b/c_api/index_io_c_ex.h
index 31f0339477..b0217bdab8 100644
--- a/c_api/index_io_c_ex.h
+++ b/c_api/index_io_c_ex.h
@@ -38,6 +38,8 @@ int faiss_write_index_buf(const FaissIndex* idx, size_t* buf_size, uint8_t** buf
 int faiss_read_index_buf(const uint8_t* buf, size_t limit, int io_flags,
         FaissIndex** p_out);
 
+void faiss_free_buf(uint8_t** buf);
+
 #ifdef __cplusplus
 }
 #endif