diff --git a/tests/test_modularization_governance.py b/tests/test_modularization_governance.py
index af39636..7be14bc 100644
--- a/tests/test_modularization_governance.py
+++ b/tests/test_modularization_governance.py
@@ -1,3 +1,4 @@
+import re
 from pathlib import Path
 
 
@@ -41,6 +42,34 @@ def test_large_python_modules_are_tracked_in_modularization_inventory():
     assert missing == []
 
 
+def test_modularization_inventory_line_counts_are_current_enough():
+    inventory = INVENTORY.read_text(encoding="utf-8")
+    inventory_counts = {
+        match.group("path"): int(match.group("lines"))
+        for match in re.finditer(
+            r"^\|\s*(?P<lines>\d+)\s*\|\s*`(?P<path>[^`]+)`\s*\|",
+            inventory,
+            re.MULTILINE,
+        )
+    }
+    large_modules = {
+        path: lines
+        for path, lines in _python_line_counts()
+        if lines >= 800
+    }
+
+    stale = []
+    for path, current_lines in sorted(large_modules.items()):
+        recorded_lines = inventory_counts.get(path)
+        if recorded_lines is None:
+            continue
+        allowed_drift = max(50, int(current_lines * 0.1))
+        if abs(recorded_lines - current_lines) > allowed_drift:
+            stale.append(f"{path}: recorded={recorded_lines}, current={current_lines}")
+
+    assert stale == []
+
+
 def test_modularization_governance_is_indexed_for_codex_sessions():
     agents = (ROOT / "AGENTS.md").read_text(encoding="utf-8")
     constitution = (ROOT / "CONSTITUTION.md").read_text(encoding="utf-8")