diff --git a/docs/changelog.rst b/docs/changelog.rst
index 62f77071..3c7350b5 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -298,6 +298,10 @@ Core Library
   was configured. This would lead to connection timeouts due to the hung
   response.
 
+* `#414 <https://github.com/dw/mitogen/issues/414>`_,
+  `#425 <https://github.com/dw/mitogen/issues/425>`_: avoid deadlock of forked
+  children by reinitializing the :mod:`mitogen.service` pool lock.
+
 * `#416 <https://github.com/dw/mitogen/issues/416>`_: around 1.4KiB of memory
   was leaked on every RPC, due to a list of strong references keeping alive any
   handler ever registered for disconnect notification.
diff --git a/mitogen/fork.py b/mitogen/fork.py
index 3e3a98a9..8636bd13 100644
--- a/mitogen/fork.py
+++ b/mitogen/fork.py
@@ -85,6 +85,10 @@ def on_fork():
     mitogen.core.Latch._on_fork()
     mitogen.core.Side._on_fork()
 
+    mitogen__service = sys.modules.get('mitogen.service')
+    if mitogen__service:
+        mitogen__service._pool_lock = threading.Lock()
+
 
 def handle_child_crash():
     """