diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 403dc81b13e..6d27301a705 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -1751,7 +1751,7 @@ class LoggerAdapter(object):
     information in logging output.
     """
 
-    def __init__(self, logger, extra):
+    def __init__(self, logger, extra=None):
         """
         Initialize the adapter with a logger and a dict-like object which
         provides contextual information. This constructor signature allows
diff --git a/Misc/NEWS.d/next/Library/2020-05-24-11-06-37.bpo-40756.7ZH83z.rst b/Misc/NEWS.d/next/Library/2020-05-24-11-06-37.bpo-40756.7ZH83z.rst
new file mode 100644
index 00000000000..a970f5be156
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-05-24-11-06-37.bpo-40756.7ZH83z.rst
@@ -0,0 +1,2 @@
+The second argument (extra) of ``LoggerAdapter.__init__`` now defaults to
+None.