diff --git a/django/contrib/auth/hashers.py b/django/contrib/auth/hashers.py
index 86ae7f42a8..e53e4da193 100644
--- a/django/contrib/auth/hashers.py
+++ b/django/contrib/auth/hashers.py
@@ -265,7 +265,7 @@ class PBKDF2PasswordHasher(BasePasswordHasher):
     safely but you must rename the algorithm if you change SHA256.
     """
     algorithm = "pbkdf2_sha256"
-    iterations = 260000
+    iterations = 320000
     digest = hashlib.sha256
 
     def encode(self, password, salt, iterations=None):
diff --git a/docs/releases/4.0.txt b/docs/releases/4.0.txt
index c8106e2d39..52531c1266 100644
--- a/docs/releases/4.0.txt
+++ b/docs/releases/4.0.txt
@@ -42,7 +42,8 @@ Minor features
 :mod:`django.contrib.auth`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-* ...
+* The default iteration count for the PBKDF2 password hasher is increased from
+  260,000 to 320,000.
 
 :mod:`django.contrib.contenttypes`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/tests/auth_tests/test_hashers.py b/tests/auth_tests/test_hashers.py
index 8bc61bc8b2..411bcea8e9 100644
--- a/tests/auth_tests/test_hashers.py
+++ b/tests/auth_tests/test_hashers.py
@@ -63,7 +63,7 @@ class TestUtilsHashPass(SimpleTestCase):
 
     def test_pbkdf2(self):
         encoded = make_password('lètmein', 'seasalt', 'pbkdf2_sha256')
-        self.assertEqual(encoded, 'pbkdf2_sha256$260000$seasalt$YlZ2Vggtqdc61YjArZuoApoBh9JNGYoDRBUGu6tcJQo=')
+        self.assertEqual(encoded, 'pbkdf2_sha256$320000$seasalt$Toj2II2rBvFiGQcPmUml1Nlni2UtvyRWwz/jz4q6q/4=')
         self.assertTrue(is_password_usable(encoded))
         self.assertTrue(check_password('lètmein', encoded))
         self.assertFalse(check_password('lètmeinz', encoded))
@@ -314,13 +314,13 @@ class TestUtilsHashPass(SimpleTestCase):
     def test_low_level_pbkdf2(self):
         hasher = PBKDF2PasswordHasher()
         encoded = hasher.encode('lètmein', 'seasalt2')
-        self.assertEqual(encoded, 'pbkdf2_sha256$260000$seasalt2$UCGMhrOoaq1ghQPArIBK5RkI6IZLRxlIwHWA1dMy7y8=')
+        self.assertEqual(encoded, 'pbkdf2_sha256$320000$seasalt2$BRr4pYNIQDsLFP+u4dzjs7pFuWJEin4lFMMoO9wBYvo=')
         self.assertTrue(hasher.verify('lètmein', encoded))
 
     def test_low_level_pbkdf2_sha1(self):
         hasher = PBKDF2SHA1PasswordHasher()
         encoded = hasher.encode('lètmein', 'seasalt2')
-        self.assertEqual(encoded, 'pbkdf2_sha1$260000$seasalt2$wAibXvW6jgvatCdONi6SMJ6q7mI=')
+        self.assertEqual(encoded, 'pbkdf2_sha1$320000$seasalt2$sDOkTvzV93jPWTRVxFGh50Jefo0=')
         self.assertTrue(hasher.verify('lètmein', encoded))
 
     @skipUnless(bcrypt, 'bcrypt not installed')