diff --git a/src/lib_io.c b/src/lib_io.c
index a54a234d..3f413fc2 100644
--- a/src/lib_io.c
+++ b/src/lib_io.c
@@ -46,7 +46,10 @@ LUA_DATA_API size_t (*lj_fwrite)(
 LUA_DATA_API int (*lj_ferror)
 (FILE *_Stream) = ferror;
 
-#if LJ_TARGET_POSIX
+#if LJ_TARGET_OSX
+LUA_DATA_API int (*lj_fseeko)(FILE *__stream, off_t __off, int __whence) = fseeko;
+LUA_DATA_API off_t (*lj_ftello)(FILE *_Stream) = ftello;
+#elif LJ_TARGET_POSIX
 LUA_DATA_API int (*lj_fseeko)(FILE *__stream, __off_t __off, int __whence) = fseeko;
 LUA_DATA_API __off64_t (*lj_ftello)(FILE *_Stream) = ftello;
 #elif _MSC_VER >= 1400