diff --git a/backend-java/src/test/java/com/nanri/aiimage/config/HttpClientTimeoutEffectiveTest.java b/backend-java/src/test/java/com/nanri/aiimage/config/HttpClientTimeoutEffectiveTest.java
index 600855d6..eda88242 100644
--- a/backend-java/src/test/java/com/nanri/aiimage/config/HttpClientTimeoutEffectiveTest.java
+++ b/backend-java/src/test/java/com/nanri/aiimage/config/HttpClientTimeoutEffectiveTest.java
@@ -126,7 +126,9 @@ class HttpClientTimeoutEffectiveTest {
         RestClient client = clientWithReadTimeout(200);
         ResourceAccessException ex = assertThrows(ResourceAccessException.class,
                 () -> client.get().uri(baseUrl() + "/slow?ms=2000").retrieve().toBodilessEntity());
-        assertTrue(root(ex) instanceof TimeoutException, "根因应为 java.util.concurrent.TimeoutException，实际 " + root(ex));
+        // JDK 在负载下可能抛 java.util.concurrent.TimeoutException 或 java.net.http.HttpTimeoutException，
+        // 两者同属"超时"；按超时语义断言而非绑定具体类型。
+        assertTrue(isTimeoutRoot(ex), "根因应为超时异常，实际 " + root(ex));
     }
 
     @Test