diff --git a/graphify/watch.py b/graphify/watch.py
index 58028eae0..5d8c07080 100644
--- a/graphify/watch.py
+++ b/graphify/watch.py
@@ -1428,6 +1428,20 @@ def _rebuild_code(
         )
         code_files = [Path(f) for f in detected['files']['code']]
 
+        # #3511: `graphify extract` has surfaced files it saw but could not
+        # classify since #1692; this update/watch rebuild path never did,
+        # so a corpus in a language with no extractor (no supported
+        # extension or shebang) rebuilt "successfully" with those files
+        # silently absent from the graph. Same wording as the extract path.
+        _unclassified = detected.get("unclassified", []) if isinstance(detected, dict) else []
+        if _unclassified:
+            _names = ", ".join(sorted({Path(p).name for p in _unclassified})[:6])
+            _more = f" (+{len(_unclassified) - 6} more)" if len(_unclassified) > 6 else ""
+            print(
+                f"[graphify watch] {len(_unclassified)} file(s) not classified "
+                f"(no supported extension or shebang), skipped: {_names}{_more}"
+            )
+
         # #2495: hand reconcile the same ignore decisions the detect() call
         # above made, so a newly-ignored file that still exists on disk is
         # purged from the graph instead of preserved forever by the fail-closed
@@ -1876,6 +1890,7 @@ def _rebuild_code(
             "files": {"code": [str(f) for f in code_files], "document": [], "paper": [], "image": []},
             "total_files": len(code_files),
             "total_words": detected.get("total_words", 0),
+            "unclassified": detected.get("unclassified", []),
         }
 
         # Inherit the existing graph's directed flag (#2342) so `graphify
diff --git a/tests/test_watch.py b/tests/test_watch.py
index da7d05933..412edb218 100644
--- a/tests/test_watch.py
+++ b/tests/test_watch.py
@@ -133,6 +133,25 @@ def test_doc_only_deletion_full_rebuild_evicts_md_nodes(tmp_path):
     assert "run()" in labels
 
 
+def test_rebuild_code_reports_unclassified_files(tmp_path, capsys):
+    """#3511: `graphify extract` has surfaced files it saw but could not
+    classify (no supported extension/shebang) since #1692; the update/watch
+    rebuild path never did, so a corpus mostly in an unsupported language
+    (e.g. Lean, per the report) rebuilt "successfully" with those files
+    silently absent and nothing said about it."""
+    corpus = tmp_path / "corpus"
+    corpus.mkdir()
+    (corpus / "app.py").write_text("def run(): pass\n", encoding="utf-8")
+    (corpus / "Main.lean").write_text("def main := 0\n", encoding="utf-8")
+    (corpus / "Util.lean").write_text("def util := 1\n", encoding="utf-8")
+
+    assert _rebuild_code(corpus, acquire_lock=False) is True
+    out = capsys.readouterr().out
+    assert "2 file(s) not classified" in out
+    assert "Main.lean" in out
+    assert "Util.lean" in out
+
+
 # --- watch() import error without watchdog ---
 
 def test_check_update_no_flag_returns_true(tmp_path):