diff --git a/torch_geometric/utils/rag/backend_utils.py b/torch_geometric/utils/rag/backend_utils.py
index 19b2da0656d4..7a89e0f922d8 100644
--- a/torch_geometric/utils/rag/backend_utils.py
+++ b/torch_geometric/utils/rag/backend_utils.py
@@ -246,8 +246,11 @@ def make_pcst_filter(triples: List[Tuple[str, str, str]],
         raise Exception("PCST requires `pip install pandas`")
     all_nodes = []
     for triple in triples:
-        all_nodes += [triple[0]] + [triple[2]]
-    full_textual_nodes = list(set(all_nodes))
+        if triple[0] in all_nodes:
+            all_nodes.append(all_nodes)
+        if triple[2] in all_nodes:
+            all_nodes.append(all_nodes)
+    full_textual_nodes = all_nodes
 
     def apply_retrieval_via_pcst(
         graph: Data,