diff --git a/core-buffer/external/bitshuffle/bitshuffle_core.h b/core-buffer/external/bitshuffle/bitshuffle_core.h
index 0250c04..912b8d7 100644
--- a/core-buffer/external/bitshuffle/bitshuffle_core.h
+++ b/core-buffer/external/bitshuffle/bitshuffle_core.h
@@ -149,6 +149,9 @@ int64_t bshuf_bitshuffle(const void* in, void* out, const size_t size,
 int64_t bshuf_bitunshuffle(const void* in, void* out, const size_t size,
         const size_t elem_size, size_t block_size);
 
+void bshuf_write_uint64_BE(void* buf, uint64_t num);
+void bshuf_write_uint32_BE(void* buf, uint32_t num);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif