diff --git a/README.md b/README.md
index 11f7b51..aaf6105 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 <div align="center">
-  <a href="http://tianshou.readthedocs.io"><img width="300px" height="auto" src="docs/_static/images/tianshou-logo.png"></a>
+  <a href="http://tianshou.readthedocs.io"><img width="300px" height="auto" src="https://github.com/thu-ml/tianshou/raw/master/docs/_static/images/tianshou-logo.png"></a>
 </div>
 
 ---
@@ -275,7 +275,7 @@ $ python3 test/discrete/test_pg.py --seed 0 --render 0.03
 ```
 
 <div align="center">
-  <img src="docs/_static/images/testpg.gif"></a>
+  <img src="https://github.com/thu-ml/tianshou/raw/master/docs/_static/images/testpg.gif"></a>
 </div>
 
 ## Contributing
diff --git a/test/base/test_env.py b/test/base/test_env.py
index 348dd84..7e507c4 100644
--- a/test/base/test_env.py
+++ b/test/base/test_env.py
@@ -78,7 +78,8 @@ def test_async_env(size=10000, num=8, sleep=0.1):
         Batch.cat(o)
         v.close()
         # assure 1/7 improvement
-        if sys.platform == "linux":  # macOS/Windows cannot pass this check
+        if sys.platform == "linux" and cls != RayVectorEnv:
+            # macOS/Windows cannot pass this check
             assert spent_time < 6.0 * sleep * num / (num + 1)