diff --git a/fruitshorts-module-content/src/test/java/com/fruitshorts/content/service/DramaServiceTest.java b/fruitshorts-module-content/src/test/java/com/fruitshorts/content/service/DramaServiceTest.java
index 4b4baca..47095c2 100644
--- a/fruitshorts-module-content/src/test/java/com/fruitshorts/content/service/DramaServiceTest.java
+++ b/fruitshorts-module-content/src/test/java/com/fruitshorts/content/service/DramaServiceTest.java
@@ -122,10 +122,30 @@ class DramaServiceTest {
         dramaService.update(DRAMA_ID, saveReq(3, UNLOCK_COIN));
 
         assertThat(episodeUpdates.get()).isZero();
-        verify(dramaEpisodeMapper, never()).selectList(any());
+        verify(dramaEpisodeMapper, times(1)).selectList(any());
         verify(dramaEpisodeMapper, never()).updateById(any(DramaEpisode.class));
     }
 
+    /**
+     * 历史漂移：短剧 freeEpisodes/unlockCoin 已是目标值，但分集 is_free 仍是旧规则。
+     * 同值重存必须纠偏，不能因「规则字段未变」短路跳过同步。
+     */
+    @Test
+    void should_correct_drifted_episode_is_free_when_free_episodes_and_unlock_coin_unchanged() {
+        givenExistingDrama(9, UNLOCK_COIN);
+        // 规则已是免费 9 集，分集仍按旧规则只免费到第 4 集（5~9 仍收费）
+        seedEpisodesAlignedToFree(4, 9);
+
+        dramaService.update(DRAMA_ID, saveReq(9, UNLOCK_COIN));
+
+        Map<Integer, DramaEpisode> byEpNo = episodeMap();
+        for (int epNo = 1; epNo <= 9; epNo++) {
+            assertThat(byEpNo.get(epNo).getIsFree()).isEqualTo(1);
+            assertThat(byEpNo.get(epNo).getUnlockCoin()).isZero();
+        }
+        verify(dramaEpisodeMapper, times(5)).updateById(any(DramaEpisode.class));
+    }
+
     @Test
     void should_not_fail_when_drama_has_no_episodes() {
         givenExistingDrama(3, UNLOCK_COIN);