diff --git a/django/contrib/auth/hashers.py b/django/contrib/auth/hashers.py
index cac11dfd4c..619f61ee3b 100644
--- a/django/contrib/auth/hashers.py
+++ b/django/contrib/auth/hashers.py
@@ -271,7 +271,7 @@ class PBKDF2PasswordHasher(BasePasswordHasher):
     safely but you must rename the algorithm if you change SHA256.
     """
     algorithm = "pbkdf2_sha256"
-    iterations = 320000
+    iterations = 390000
     digest = hashlib.sha256
 
     def encode(self, password, salt, iterations=None):
diff --git a/docs/releases/4.1.txt b/docs/releases/4.1.txt
index 9066d47ac7..ee0a773f5d 100644
--- a/docs/releases/4.1.txt
+++ b/docs/releases/4.1.txt
@@ -42,7 +42,8 @@ Minor features
 :mod:`django.contrib.auth`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-* ...
+* The default iteration count for the PBKDF2 password hasher is increased from
+  320,000 to 390,000.
 
 :mod:`django.contrib.contenttypes`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/tests/auth_tests/test_hashers.py b/tests/auth_tests/test_hashers.py
index dda64971ba..2b8b953026 100644
--- a/tests/auth_tests/test_hashers.py
+++ b/tests/auth_tests/test_hashers.py
@@ -64,7 +64,7 @@ class TestUtilsHashPass(SimpleTestCase):
 
     def test_pbkdf2(self):
         encoded = make_password('lètmein', 'seasalt', 'pbkdf2_sha256')
-        self.assertEqual(encoded, 'pbkdf2_sha256$320000$seasalt$Toj2II2rBvFiGQcPmUml1Nlni2UtvyRWwz/jz4q6q/4=')
+        self.assertEqual(encoded, 'pbkdf2_sha256$390000$seasalt$8xBlGd3jVgvJ+92hWPxi5ww0uuAuAnKgC45eudxro7c=')
         self.assertTrue(is_password_usable(encoded))
         self.assertTrue(check_password('lètmein', encoded))
         self.assertFalse(check_password('lètmeinz', encoded))
@@ -346,13 +346,13 @@ class TestUtilsHashPass(SimpleTestCase):
     def test_low_level_pbkdf2(self):
         hasher = PBKDF2PasswordHasher()
         encoded = hasher.encode('lètmein', 'seasalt2')
-        self.assertEqual(encoded, 'pbkdf2_sha256$320000$seasalt2$BRr4pYNIQDsLFP+u4dzjs7pFuWJEin4lFMMoO9wBYvo=')
+        self.assertEqual(encoded, 'pbkdf2_sha256$390000$seasalt2$geC/uZ92nRXDSjSxeoiBqYyRcrLzMm8xK3ro1QS1uo8=')
         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$320000$seasalt2$sDOkTvzV93jPWTRVxFGh50Jefo0=')
+        self.assertEqual(encoded, 'pbkdf2_sha1$390000$seasalt2$aDapRanzW8aHTz97v2TcfHzWD+I=')
         self.assertTrue(hasher.verify('lètmein', encoded))
 
     @skipUnless(bcrypt, 'bcrypt not installed')