diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index e1b8500..b7a10ac 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -4,7 +4,7 @@ repos:
     hooks:
       - id: isort
   - repo: https://github.com/psf/black
-    rev: 20.8b1
+    rev: 21.4b0
     hooks:
       - id: black
   - repo: https://github.com/PyCQA/flake8
diff --git a/napari_plugin_engine/manager.py b/napari_plugin_engine/manager.py
index ff49439..978d586 100644
--- a/napari_plugin_engine/manager.py
+++ b/napari_plugin_engine/manager.py
@@ -406,7 +406,7 @@ def _register_dict(
         return self.register(namespace, name)
 
     def get_name(self, plugin):
-        """ Return name for registered plugin or ``None`` if not registered. """
+        """Return name for registered plugin or ``None`` if not registered."""
         for name, val in self.plugins.items():
             if plugin == val:
                 return name
@@ -662,7 +662,7 @@ def check_pending(self):
                         )
 
     def get_hookcallers(self, plugin: Any) -> Optional[List[HookCaller]]:
-        """ get all hook callers for the specified plugin. """
+        """get all hook callers for the specified plugin."""
         return self._plugin2hookcallers.get(plugin)
 
     def add_hookcall_monitoring(
@@ -706,7 +706,7 @@ def undo():
         return undo
 
     def enable_tracing(self):
-        """Enable tracing of hook calls and return an undo function. """
+        """Enable tracing of hook calls and return an undo function."""
         hooktrace = self.trace.root.get("hook")
 
         def before(hook_name, methods, kwargs):