diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index dd8744a..2b65e8a 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
 -   repo: https://github.com/psf/black
-    rev: 20.8b1
+    rev: 21.4b0
     hooks:
     -   id: black
         args: [--safe, --quiet, --target-version, py35]
@@ -17,7 +17,7 @@ repos:
     hooks:
     -   id: flake8
 -   repo: https://github.com/asottile/pyupgrade
-    rev: v2.12.0
+    rev: v2.13.0
     hooks:
     -   id: pyupgrade
         args: [--py3-plus]
diff --git a/src/xdist/dsession.py b/src/xdist/dsession.py
index ccd5e20..d517a8a 100644
--- a/src/xdist/dsession.py
+++ b/src/xdist/dsession.py
@@ -14,7 +14,7 @@ from queue import Empty, Queue
 
 
 class Interrupted(KeyboardInterrupt):
-    """ signals an immediate interruption. """
+    """signals an immediate interruption."""
 
 
 class DSession:
diff --git a/src/xdist/newhooks.py b/src/xdist/newhooks.py
index a6443f3..d2482af 100644
--- a/src/xdist/newhooks.py
+++ b/src/xdist/newhooks.py
@@ -15,36 +15,36 @@ import pytest
 
 
 def pytest_xdist_setupnodes(config, specs):
-    """ called before any remote node is set up. """
+    """called before any remote node is set up."""
 
 
 def pytest_xdist_newgateway(gateway):
-    """ called on new raw gateway creation. """
+    """called on new raw gateway creation."""
 
 
 def pytest_xdist_rsyncstart(source, gateways):
-    """ called before rsyncing a directory to remote gateways takes place. """
+    """called before rsyncing a directory to remote gateways takes place."""
 
 
 def pytest_xdist_rsyncfinish(source, gateways):
-    """ called after rsyncing a directory to remote gateways takes place. """
+    """called after rsyncing a directory to remote gateways takes place."""
 
 
 @pytest.mark.firstresult
 def pytest_xdist_getremotemodule():
-    """ called when creating remote node"""
+    """called when creating remote node"""
 
 
 def pytest_configure_node(node):
-    """ configure node information before it gets instantiated. """
+    """configure node information before it gets instantiated."""
 
 
 def pytest_testnodeready(node):
-    """ Test Node is ready to operate. """
+    """Test Node is ready to operate."""
 
 
 def pytest_testnodedown(node, error):
-    """ Test Node is down. """
+    """Test Node is down."""
 
 
 def pytest_xdist_node_collection_finished(node, ids):
@@ -53,7 +53,7 @@ def pytest_xdist_node_collection_finished(node, ids):
 
 @pytest.mark.firstresult
 def pytest_xdist_make_scheduler(config, log):
-    """ return a node scheduler implementation """
+    """return a node scheduler implementation"""
 
 
 @pytest.mark.firstresult
diff --git a/src/xdist/workermanage.py b/src/xdist/workermanage.py
index 19ed73a..8fed077 100644
--- a/src/xdist/workermanage.py
+++ b/src/xdist/workermanage.py
@@ -293,7 +293,7 @@ class WorkerController:
             self._shutdown_sent = True
 
     def sendcommand(self, name, **kwargs):
-        """ send a named parametrized command to the other side. """
+        """send a named parametrized command to the other side."""
         self.log("sending command {}(**{})".format(name, kwargs))
         self.channel.send((name, kwargs))