diff --git a/src/fileops.c b/src/fileops.c
index 3d35c193f..5de89cbd8 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -133,7 +133,7 @@ void gitfo_free_map(git_map *out)
 /* cached diskio */
 struct gitfo_cache {
 	git_file fd;
-	unsigned int cache_size, pos;
+	size_t cache_size, pos;
 	unsigned char *cache;
 };