diff --git a/README.rst b/README.rst
index 577c39e..a824013 100644
--- a/README.rst
+++ b/README.rst
@@ -166,6 +166,8 @@ UNRELEASED
 ==========
 
 * Dropped support for Python 2.
+* Updated default pickle protocol to version 3.
+
 Changes in version 2.1.0
 ========================
 
diff --git a/picklefield/constants.py b/picklefield/constants.py
index d3c1743..e8232d2 100644
--- a/picklefield/constants.py
+++ b/picklefield/constants.py
@@ -1,3 +1,3 @@
 from __future__ import unicode_literals
 
-DEFAULT_PROTOCOL = 2
+DEFAULT_PROTOCOL = 3