diff --git a/source/blender/blenkernel/intern/node.c b/source/blender/blenkernel/intern/node.c
index 292f38b9472..d40b030c470 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -398,6 +398,11 @@ bNode *nodeCopyNode(struct bNodeTree *ntree, struct bNode *node)
 		sock->stack_index= 0;
 		
 		sock->default_value = (oldsock->default_value ? MEM_dupallocN(oldsock->default_value) : NULL);
+		
+		/* XXX some compositor node (e.g. image, render layers) still store
+		 * some persistent buffer data here, need to clear this to avoid dangling pointers.
+		 */
+		sock->cache = NULL;
 	}
 	
 	BLI_duplicatelist(&nnode->outputs, &node->outputs);
@@ -407,6 +412,11 @@ bNode *nodeCopyNode(struct bNodeTree *ntree, struct bNode *node)
 		sock->stack_index= 0;
 		
 		sock->default_value = (oldsock->default_value ? MEM_dupallocN(oldsock->default_value) : NULL);
+		
+		/* XXX some compositor node (e.g. image, render layers) still store
+		 * some persistent buffer data here, need to clear this to avoid dangling pointers.
+		 */
+		sock->cache = NULL;
 	}
 	
 	/* don't increase node->id users, freenode doesn't decrement either */
diff --git a/source/blender/nodes/composite/node_composite_tree.c b/source/blender/nodes/composite/node_composite_tree.c
index 9593e61beb6..01e46ed3df9 100644
--- a/source/blender/nodes/composite/node_composite_tree.c
+++ b/source/blender/nodes/composite/node_composite_tree.c
@@ -362,7 +362,7 @@ static int setExecutableNodes(bNodeTreeExec *exec, ThreadData *thd)
 		int a;
 		node = nodeexec->node;
 		
-		node_get_stack(node, thd->stack, nsin, nsout);
+		node_get_stack(node, exec->stack, nsin, nsout);
 		
 		/* test the outputs */
 		/* skip value-only nodes (should be in type!) */
@@ -428,7 +428,7 @@ static int setExecutableNodes(bNodeTreeExec *exec, ThreadData *thd)
 			node = nodeexec->node;
 			if(node->need_exec==0 && node_only_value(node)) {
 				if(node->typeinfo->execfunc) {
-					node_get_stack(node, thd->stack, nsin, nsout);
+					node_get_stack(node, exec->stack, nsin, nsout);
 					node->typeinfo->execfunc(thd->rd, node, nsin, nsout);
 				}
 			}