diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index b9d786e35a1..78f857057df 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -25,6 +25,7 @@ use Drupal\field\FieldConfigInterface;
 use Drupal\field\FieldStorageConfigInterface;
 use Drupal\node\NodeInterface;
 use Drupal\user\RoleInterface;
+use Drupal\user\UserInterface;
 
 /**
  * Anonymous posters cannot enter their contact information.
@@ -518,7 +519,7 @@ function comment_node_search_result(EntityInterface $node) {
 /**
  * Implements hook_user_cancel().
  */
-function comment_user_cancel($edit, $account, $method) {
+function comment_user_cancel($edit, UserInterface $account, $method) {
   switch ($method) {
     case 'user_cancel_block_unpublish':
       $comments = entity_load_multiple_by_properties('comment', ['uid' => $account->id()]);
diff --git a/core/modules/history/history.module b/core/modules/history/history.module
index 5e9268be5d8..44dfb139243 100644
--- a/core/modules/history/history.module
+++ b/core/modules/history/history.module
@@ -12,6 +12,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\user\UserInterface;
 
 /**
  * Entities changed before this time are always shown as read.
@@ -159,7 +160,7 @@ function history_node_delete(EntityInterface $node) {
 /**
  * Implements hook_user_cancel().
  */
-function history_user_cancel($edit, $account, $method) {
+function history_user_cancel($edit, UserInterface $account, $method) {
   switch ($method) {
     case 'user_cancel_reassign':
       \Drupal::database()->delete('history')
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index 55c71cd6034..425182cac6a 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -28,6 +28,7 @@ use Drupal\node\Entity\Node;
 use Drupal\node\Entity\NodeType;
 use Drupal\node\NodeInterface;
 use Drupal\node\NodeTypeInterface;
+use Drupal\user\UserInterface;
 
 /**
  * Denotes that the node is not published.
@@ -713,7 +714,7 @@ function node_ranking() {
 /**
  * Implements hook_user_cancel().
  */
-function node_user_cancel($edit, $account, $method) {
+function node_user_cancel($edit, UserInterface $account, $method) {
   switch ($method) {
     case 'user_cancel_block_unpublish':
       // Unpublish nodes (current revisions).
diff --git a/core/modules/system/tests/modules/session_test/session_test.module b/core/modules/system/tests/modules/session_test/session_test.module
index b3ceff80a5c..6eb48afbc71 100644
--- a/core/modules/system/tests/modules/session_test/session_test.module
+++ b/core/modules/system/tests/modules/session_test/session_test.module
@@ -5,10 +5,12 @@
  * Test module.
  */
 
+use Drupal\user\UserInterface;
+
 /**
  * Implements hook_user_login().
  */
-function session_test_user_login($account) {
+function session_test_user_login(UserInterface $account) {
   if ($account->getUsername() == 'session_test_user') {
     // Exit so we can verify that the session was regenerated
     // before hook_user_login() was called.
diff --git a/core/modules/user/tests/modules/user_hooks_test/user_hooks_test.module b/core/modules/user/tests/modules/user_hooks_test/user_hooks_test.module
index cafaf908a38..5f3d19d0333 100644
--- a/core/modules/user/tests/modules/user_hooks_test/user_hooks_test.module
+++ b/core/modules/user/tests/modules/user_hooks_test/user_hooks_test.module
@@ -6,11 +6,12 @@
  */
 
 use Drupal\Component\Render\FormattableMarkup;
+use Drupal\Core\Session\AccountInterface;
 
 /**
  * Implements hook_user_format_name_alter().
  */
-function user_hooks_test_user_format_name_alter(&$name, $account) {
+function user_hooks_test_user_format_name_alter(&$name, AccountInterface $account) {
   if (\Drupal::state()->get('user_hooks_test_user_format_name_alter', FALSE)) {
     if (\Drupal::state()->get('user_hooks_test_user_format_name_alter_safe', FALSE)) {
       $name = new FormattableMarkup('<em>@uid</em>', ['@uid' => $account->id()]);
diff --git a/core/modules/user/user.api.php b/core/modules/user/user.api.php
index f177088ae1b..cddcda7d305 100644
--- a/core/modules/user/user.api.php
+++ b/core/modules/user/user.api.php
@@ -5,6 +5,9 @@
  * Hooks provided by the User module.
  */
 
+use Drupal\Core\Session\AccountInterface;
+use Drupal\user\UserInterface;
+
 /**
  * @addtogroup hooks
  * @{
@@ -28,7 +31,7 @@
  *
  * @param array $edit
  *   The array of form values submitted by the user.
- * @param \Drupal\Core\Session\AccountInterface $account
+ * @param \Drupal\user\UserInterface $account
  *   The user object on which the operation is being performed.
  * @param string $method
  *   The account cancellation method.
@@ -36,7 +39,7 @@
  * @see user_cancel_methods()
  * @see hook_user_cancel_methods_alter()
  */
-function hook_user_cancel($edit, $account, $method) {
+function hook_user_cancel($edit, UserInterface $account, $method) {
   switch ($method) {
     case 'user_cancel_block_unpublish':
       // Unpublish nodes (current revisions).
@@ -120,7 +123,7 @@ function hook_user_cancel_methods_alter(&$methods) {
  * @see \Drupal\Core\Session\AccountInterface::getDisplayName()
  * @see sanitization
  */
-function hook_user_format_name_alter(&$name, $account) {
+function hook_user_format_name_alter(&$name, AccountInterface $account) {
   // Display the user's uid instead of name.
   if ($account->id()) {
     $name = t('User @uid', ['@uid' => $account->id()]);
@@ -130,10 +133,10 @@ function hook_user_format_name_alter(&$name, $account) {
 /**
  * The user just logged in.
  *
- * @param object $account
+ * @param \Drupal\user\UserInterface $account
  *   The user object on which the operation was just performed.
  */
-function hook_user_login($account) {
+function hook_user_login(UserInterface $account) {
   $config = \Drupal::config('system.date');
   // If the user has a NULL time zone, notify them to set a time zone.
   if (!$account->getTimezone() && $config->get('timezone.user.configurable') && $config->get('timezone.user.warn')) {
@@ -151,10 +154,10 @@ function hook_user_login($account) {
 /**
  * The user just logged out.
  *
- * @param $account
+ * @param \Drupal\Core\Session\AccountInterface $account
  *   The user object on which the operation was just performed.
  */
-function hook_user_logout($account) {
+function hook_user_logout(AccountInterface $account) {
   \Drupal::database()->insert('logouts')
     ->fields([
       'uid' => $account->id(),
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index b18408ab5f1..053429f4b87 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -569,7 +569,7 @@ function user_login_finalize(UserInterface $account) {
 /**
  * Implements hook_user_login().
  */
-function user_user_login($account) {
+function user_user_login(UserInterface $account) {
   // Reset static cache of default variables in template_preprocess() to reflect
   // the new user.
   drupal_static_reset('template_preprocess');
@@ -578,7 +578,7 @@ function user_user_login($account) {
 /**
  * Implements hook_user_logout().
  */
-function user_user_logout($account) {
+function user_user_logout(AccountInterface $account) {
   // Reset static cache of default variables in template_preprocess() to reflect
   // the new user.
   drupal_static_reset('template_preprocess');