diff --git a/src/flake8/checker.py b/src/flake8/checker.py
index 4fb106e..32e58af 100644
--- a/src/flake8/checker.py
+++ b/src/flake8/checker.py
@@ -435,7 +435,8 @@ class FileChecker(object):
             return plugin["plugin"](**arguments)
         except Exception as all_exc:
             LOG.critical(
-                "Plugin %s raised an unexpected exception", plugin["name"]
+                "Plugin %s raised an unexpected exception", plugin["name"],
+                exc_info=True
             )
             raise exceptions.PluginExecutionFailed(
                 plugin=plugin, exception=all_exc