diff --git a/graphrag/entity_resolution.py b/graphrag/entity_resolution.py
index a5be7226c..5d75027ea 100644
--- a/graphrag/entity_resolution.py
+++ b/graphrag/entity_resolution.py
@@ -111,7 +111,7 @@ class EntityResolution(Extractor):
         connect_graph.add_edges_from(resolution_result)
         async with trio.open_nursery() as nursery:
             for sub_connect_graph in nx.connected_components(connect_graph):
-                merging_nodes = list(sub_connect_graph.nodes())
+                merging_nodes = list(sub_connect_graph)
                 nursery.start_soon(lambda: self._merge_graph_nodes(graph, merging_nodes, change))
 
         # Update pagerank
diff --git a/graphrag/general/extractor.py b/graphrag/general/extractor.py
index d4f9e9946..4c6f8e11f 100644
--- a/graphrag/general/extractor.py
+++ b/graphrag/general/extractor.py
@@ -201,7 +201,7 @@ class Extractor:
             # Merge two nodes, keep "entity_name", "entity_type", "page_rank" unchanged.
             node1_attrs = graph.nodes[node1]
             node0_attrs["description"] += f"{GRAPH_FIELD_SEP}{node1_attrs['description']}"
-            node0_attrs["source_id"] = sorted(set(node0_attrs["source_id"].extend(node1_attrs.get("source_id", []))))
+            node0_attrs["source_id"] = sorted(set(node0_attrs["source_id"] + node1_attrs["source_id"]))
             for neighbor in graph.neighbors(node1):
                 change.removed_edges.add(get_from_to(node1, neighbor))
                 if neighbor not in nodes_set:
@@ -213,7 +213,7 @@ class Extractor:
                         edge0_attrs["weight"] += edge1_attrs["weight"]
                         edge0_attrs["description"] += f"{GRAPH_FIELD_SEP}{edge1_attrs['description']}"
                         for attr in ["keywords", "source_id"]:
-                            edge0_attrs[attr] = sorted(set(edge0_attrs[attr].extend(edge1_attrs.get(attr, []))))
+                            edge0_attrs[attr] = sorted(set(edge0_attrs[attr] + edge1_attrs[attr]))
                         edge0_attrs["description"] = await self._handle_entity_relation_summary(f"({nodes[0]}, {neighbor})", edge0_attrs["description"])
                         graph.add_edge(nodes[0], neighbor, **edge0_attrs)
                     else: