diff --git a/tornado/platform/twisted.py b/tornado/platform/twisted.py
index 04c9e4e56..d3d7e57c6 100644
--- a/tornado/platform/twisted.py
+++ b/tornado/platform/twisted.py
@@ -56,7 +56,7 @@ def errback(failure: failure.Failure) -> None:
                 failure.raiseException()
                 # Should never happen, but just in case
                 raise Exception("errback called without error")
-            except:
+            except Exception:
                 future_set_exc_info(f, sys.exc_info())
 
         d.addCallbacks(f.set_result, errback)