diff --git a/extent-cache.c b/extent-cache.c
index 662c801e..f458de26 100644
--- a/extent-cache.c
+++ b/extent-cache.c
@@ -93,15 +93,14 @@ void cache_tree_init(struct cache_tree *tree)
 	tree->root = RB_ROOT;
 }
 
-static struct cache_extent *
-alloc_cache_extent(u64 objectid, u64 start, u64 size)
+static struct cache_extent *alloc_cache_extent(u64 start, u64 size)
 {
 	struct cache_extent *pe = malloc(sizeof(*pe));
 
 	if (!pe)
 		return pe;
 
-	pe->objectid = objectid;
+	pe->objectid = 0;
 	pe->start = start;
 	pe->size = size;
 	return pe;
@@ -109,7 +108,7 @@ alloc_cache_extent(u64 objectid, u64 start, u64 size)
 
 int add_cache_extent(struct cache_tree *tree, u64 start, u64 size)
 {
-	struct cache_extent *pe = alloc_cache_extent(0, start, size);
+	struct cache_extent *pe = alloc_cache_extent(start, size);
 	int ret;
 
 	if (!pe) {