diff --git a/src/claridoc/style_contracts.py b/src/claridoc/style_contracts.py
index b613111..0a91ec8 100644
--- a/src/claridoc/style_contracts.py
+++ b/src/claridoc/style_contracts.py
@@ -38,7 +38,7 @@ Write Korean reader-facing prose as a supported first-person experience, not as
 - Use conversational but disciplined Korean. A Korean developer should be able to say the sentence naturally to a colleague without turning it into forced colloquial speech.
 """
 
-_PLAIN_FORM_ENDING = re.compile(r"(?<!니)다(?=[.!?](?:\s|$))")
+_PLAIN_FORM_ENDING = re.compile(r"(?<!니)다(?=(?:[.!?](?:\s|$)|$))")
 _FIRST_PERSON = re.compile(r"(?:저는|제가)")
 _FENCE = re.compile(r"^\s*(?:```|~~~)")
 _HEADING = re.compile(r"^\s{0,3}(#{1,6})\s+(.+?)\s*$")
diff --git a/tests/test_lint.py b/tests/test_lint.py
index c033359..07dea73 100644
--- a/tests/test_lint.py
+++ b/tests/test_lint.py
@@ -201,6 +201,19 @@ class LintTests(unittest.TestCase):
         self.assertEqual(issues[0].severity, Severity.BLOCKER)
         self.assertEqual(report.metrics["plain_form_ending_count"], 1)
 
+    def test_korean_experience_contract_blocks_unpunctuated_plain_ending(self) -> None:
+        brief = self._korean_experience_brief()
+        sources = make_sources()
+        text, outline = self._experience_document(
+            brief,
+            extra_by_section={0: "현재 구현은 이 값을 사용한다"},
+        )
+
+        report = lint_document(text, brief, outline, sources)
+
+        self.assertIn("STYLE002", {issue.code for issue in report.issues})
+        self.assertEqual(report.metrics["plain_form_ending_count"], 1)
+
     def test_korean_style_lint_exempts_non_reader_prose(self) -> None:
         brief = self._korean_experience_brief()
         sources = make_sources()