diff --git a/intern/cycles/bvh/bvh.cpp b/intern/cycles/bvh/bvh.cpp
index 15bd814b8d5..43b16a62207 100644
--- a/intern/cycles/bvh/bvh.cpp
+++ b/intern/cycles/bvh/bvh.cpp
@@ -794,7 +794,7 @@ void QBVH::pack_inner(const BVHStackEntry& e, const BVHStackEntry *en, int num)
 
 void QBVH::pack_nodes(const array<int>& prims, const BVHNode *root)
 {
-	size_t node_size = root->getSubtreeSize(BVH_STAT_NODE_COUNT);
+	size_t node_size = root->getSubtreeSize(BVH_STAT_QNODE_COUNT);
 
 	/* resize arrays */
 	pack.nodes.clear();
diff --git a/intern/cycles/bvh/bvh_node.cpp b/intern/cycles/bvh/bvh_node.cpp
index 7cc9bd333b0..8294690da7d 100644
--- a/intern/cycles/bvh/bvh_node.cpp
+++ b/intern/cycles/bvh/bvh_node.cpp
@@ -47,6 +47,20 @@ int BVHNode::getSubtreeSize(BVH_STAT stat) const
 		case BVH_STAT_CHILDNODE_COUNT:
 			cnt = num_children();
 			break;
+		case BVH_STAT_QNODE_COUNT:
+			cnt = 1;
+			for(int i = 0; i < num_children(); i++) {
+				BVHNode *node = get_child(i);
+				if(node->is_leaf()) {
+					cnt += 1;
+				}
+				else {
+					for(int j = 0; j < node->num_children(); j++) {
+						cnt += node->get_child(j)->getSubtreeSize(stat);
+					}
+				}
+			}
+			return cnt;
 		default:
 			assert(0); /* unknown mode */
 	}
diff --git a/intern/cycles/bvh/bvh_node.h b/intern/cycles/bvh/bvh_node.h
index a0d10a46bfc..1656bb367a4 100644
--- a/intern/cycles/bvh/bvh_node.h
+++ b/intern/cycles/bvh/bvh_node.h
@@ -30,7 +30,8 @@ enum BVH_STAT
 	BVH_STAT_INNER_COUNT,
 	BVH_STAT_LEAF_COUNT,
 	BVH_STAT_TRIANGLE_COUNT,
-	BVH_STAT_CHILDNODE_COUNT
+	BVH_STAT_CHILDNODE_COUNT,
+	BVH_STAT_QNODE_COUNT,
 };
 
 class BVHParams;