diff --git a/pack-objects.h b/pack-objects.h
index ad3c208..741e6f8 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -364,7 +364,7 @@
 				     unsigned int tree_depth)
 {
 	if (!pack->tree_depth)
-		ALLOC_ARRAY(pack->tree_depth, pack->nr_objects);
+		ALLOC_ARRAY(pack->tree_depth, pack->nr_alloc);
 	pack->tree_depth[e - pack->objects] = tree_depth;
 }
 
@@ -381,7 +381,7 @@
 				unsigned char layer)
 {
 	if (!pack->layer)
-		ALLOC_ARRAY(pack->layer, pack->nr_objects);
+		ALLOC_ARRAY(pack->layer, pack->nr_alloc);
 	pack->layer[e - pack->objects] = layer;
 }