diff --git a/graphify/extract.py b/graphify/extract.py
index 40b9c8b..ed05504 100644
--- a/graphify/extract.py
+++ b/graphify/extract.py
@@ -3450,10 +3450,16 @@ def _ruby_extra_walk(node, source: bytes, file_nid: str, stem: str, str_path: st
                         if base_nid not in seen_ids:
                             base_nid = _make_id(base)
                             if base_nid not in seen_ids:
+                                # origin_file lets _disambiguate_colliding_node_ids
+                                # tell this file's unresolved reference apart from
+                                # another file's same-named one, instead of every
+                                # file's stub collapsing onto one shared bare id
+                                # (see ensure_named_node(), which sets the same
+                                # field for this exact reason).
                                 nodes.append({
                                     "id": base_nid, "label": base,
                                     "file_type": "code", "source_file": "",
-                                    "source_location": "",
+                                    "source_location": "", "origin_file": str_path,
                                 })
                                 seen_ids.add(base_nid)
                         add_edge(class_nid, base_nid, "inherits", line)
@@ -3707,18 +3713,7 @@ def _extract_generic(
                     for arg in args.children:
                         if arg.type == "identifier":
                             base = _read_text(arg, source)
-                            base_nid = _make_id(stem, base)
-                            if base_nid not in seen_ids:
-                                base_nid = _make_id(base)
-                                if base_nid not in seen_ids:
-                                    nodes.append({
-                                        "id": base_nid,
-                                        "label": base,
-                                        "file_type": "code",
-                                        "source_file": "",
-                                        "source_location": "",
-                                    })
-                                    seen_ids.add(base_nid)
+                            base_nid = ensure_named_node(base, line)
                             add_edge(class_nid, base_nid, "inherits", line)
 
             # Swift-specific: conformance / inheritance
@@ -3857,18 +3852,7 @@ def _extract_generic(
                         base = _kotlin_user_type_name(user_type_node, source)
                         if not base:
                             continue
-                        base_nid = _make_id(stem, base)
-                        if base_nid not in seen_ids:
-                            base_nid = _make_id(base)
-                            if base_nid not in seen_ids:
-                                nodes.append({
-                                    "id": base_nid,
-                                    "label": base,
-                                    "file_type": "code",
-                                    "source_file": "",
-                                    "source_location": "",
-                                })
-                                seen_ids.add(base_nid)
+                        base_nid = ensure_named_node(base, line)
                         add_edge(class_nid, base_nid, relation, line)
                         for arg_child in user_type_node.children:
                             if arg_child.type != "type_arguments":
@@ -3902,18 +3886,7 @@ def _extract_generic(
                                 base = _read_text(consts[-1], source)
                             break
                     if base:
-                        base_nid = _make_id(stem, base)
-                        if base_nid not in seen_ids:
-                            base_nid = _make_id(base)
-                            if base_nid not in seen_ids:
-                                nodes.append({
-                                    "id": base_nid,
-                                    "label": base,
-                                    "file_type": "code",
-                                    "source_file": "",
-                                    "source_location": "",
-                                })
-                                seen_ids.add(base_nid)
+                        base_nid = ensure_named_node(base, line)
                         add_edge(class_nid, base_nid, "inherits", line)
 
                 # `include`/`extend`/`prepend <Const>` in the class/module body ->
@@ -4179,18 +4152,7 @@ def _extract_generic(
                             continue
                         if not base:
                             continue
-                        base_nid = _make_id(stem, base)
-                        if base_nid not in seen_ids:
-                            base_nid = _make_id(base)
-                            if base_nid not in seen_ids:
-                                nodes.append({
-                                    "id": base_nid,
-                                    "label": base,
-                                    "file_type": "code",
-                                    "source_file": "",
-                                    "source_location": "",
-                                })
-                                seen_ids.add(base_nid)
+                        base_nid = ensure_named_node(base, line)
                         add_edge(class_nid, base_nid, "inherits", line)
                         # Emit a generic_arg reference for each type argument on the
                         # base (Base<Dep> -> Car references Dep). _cpp_collect_type_refs
diff --git a/tests/test_extract.py b/tests/test_extract.py
index 04baf39..9254a25 100644
--- a/tests/test_extract.py
+++ b/tests/test_extract.py
@@ -100,6 +100,37 @@ def test_extract_disambiguates_duplicate_symbol_ids_by_source_path(tmp_path):
             assert edge["target"] in node_ids, f"Dangling structural target: {edge}"
 
 
+def test_cpp_unresolved_base_class_stubs_stay_disambiguated_by_file(tmp_path):
+    """Two different files' same-named, otherwise-undefined base class must not
+    collapse onto one shared stub node.
+
+    The C++ base_class_clause handler used to build its stub inline instead of
+    calling ensure_named_node(), so it never tagged the stub with origin_file.
+    Without that tag, _disambiguate_colliding_node_ids couldn't tell file A's
+    reference to unresolved `Base` apart from file B's, and every file's
+    unresolved base class merged onto one bare id -- which could then collide
+    with an unrelated same-named real definition anywhere else in the corpus.
+    """
+    first = tmp_path / "a" / "Foo.cpp"
+    second = tmp_path / "b" / "Bar.cpp"
+    first.parent.mkdir(parents=True)
+    second.parent.mkdir(parents=True)
+    first.write_text("class Foo : public Base {};\n", encoding="utf-8")
+    second.write_text("class Bar : public Base {};\n", encoding="utf-8")
+
+    result = extract([first, second], cache_root=tmp_path)
+    base_stubs = [
+        node for node in result["nodes"]
+        if node["label"] == "Base" and not node.get("source_file")
+    ]
+    assert len(base_stubs) == 2
+    assert len({node["id"] for node in base_stubs}) == 2
+
+    inherits_edges = [e for e in result["edges"] if e["relation"] == "inherits"]
+    assert len(inherits_edges) == 2
+    assert len({e["target"] for e in inherits_edges}) == 2
+
+
 def test_cross_file_type_annotation_refs_resolve_to_single_node(tmp_path):
     """#1402: a class defined once but referenced via type annotations in N other
     files must NOT create 1+N phantom duplicate nodes (with the referencing file's