diff --git a/loopx/semantics/field_use.py b/loopx/semantics/field_use.py
index 2b545757de..01703a8080 100644
--- a/loopx/semantics/field_use.py
+++ b/loopx/semantics/field_use.py
@@ -263,7 +263,11 @@ def _token_pattern(field: str) -> re.Pattern[str]:
 def lexical_module_count(field: str, suffix: str, sources: Iterable[SourceFile]) -> int:
     """The pre-B3 metric: modules whose text contains the standalone token."""
     token = _token_pattern(field)
-    return sum(1 for source in sources if source.suffix == suffix and token.search(source.text))
+    # Literal containment is a prerequisite of the same boundary regex.
+    return sum(
+        1 for source in sources
+        if source.suffix == suffix and field in source.text and token.search(source.text)
+    )
 
 
 def scan_field_uses(
diff --git a/tests/architecture/test_semantic_field_use.py b/tests/architecture/test_semantic_field_use.py
index 4051d26d81..3b3d7eaa17 100644
--- a/tests/architecture/test_semantic_field_use.py
+++ b/tests/architecture/test_semantic_field_use.py
@@ -16,6 +16,7 @@
     FACTS,
     ROLES,
     field_use_summary,
+    lexical_module_count,
     python_module_scan,
     scan_field_uses,
 )
@@ -25,6 +26,20 @@
 FIELDS = frozenset({FIELD})
 
 
+@pytest.mark.parametrize("suffix, expected", [(".py", 3), (".ts", 1)])
+def test_lexical_modules_preserve_boundaries_and_raw_source_text(suffix: str, expected: int) -> None:
+    sources = [
+        SourceFile("comment.py", ".py", "# goal_boundary goal_boundary"),
+        SourceFile("prefix.py", ".py", "goal_boundary_repair repair_goal_boundary"),
+        SourceFile("unicode.py", ".py", "汉goal_boundary字"),
+        SourceFile("escaped.py", ".py", r'"goal_\u0062oundary"'),
+        SourceFile("broken.py", ".py", "def broken(:\n# goal_boundary"),
+        SourceFile("other.ts", ".ts", "// goal_boundary"),
+        SourceFile("absent.py", ".py", "payload.get(dynamic_key)"),
+    ]
+    assert lexical_module_count(FIELD, suffix, iter(sources)) == expected
+
+
 def python(text: str) -> dict[str, set[str]]:
     return python_module_scan(ast.parse(text), FIELDS)[0]