diff --git a/functionMap.php b/functionMap.php
index 35ed6417..12045d1e 100644
--- a/functionMap.php
+++ b/functionMap.php
@@ -210,4 +210,6 @@
     'WP_Widget_Factory::unregister' => [null, 'widget' => 'class-string<\WP_Widget>|\WP_Widget'],
     'Custom_Image_Header::show_header_selector' => [null, 'type' => "'default'|'uploaded'"],
     'Custom_Image_Header::set_header_image' => [null, 'choice' => 'string|array{attachment_id: int<1, max>, url: string, width: int<0, max>, height: int<0, max>}'],
+    'get_user' => ['($user_id is int<min, 0> ? false : \WP_User|false)'],
+    'get_user_by' => ["(\$field is 'id'|'ID' ? (\$value is int<min, 0> ? false : \WP_User|false) : \WP_User|false)"],
 ];
diff --git a/tests/TypeInferenceTest.php b/tests/TypeInferenceTest.php
index 26ba0900..42067a55 100644
--- a/tests/TypeInferenceTest.php
+++ b/tests/TypeInferenceTest.php
@@ -38,6 +38,8 @@ public function dataFileAsserts(): iterable
         yield from $this->gatherAssertTypes(__DIR__ . '/data/get_taxonomies.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/get_term.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/get_taxonomies_for_attachments.php');
+        yield from $this->gatherAssertTypes(__DIR__ . '/data/get_user.php');
+        yield from $this->gatherAssertTypes(__DIR__ . '/data/get_user_by.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/has_filter.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/is_new_day.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/is_wp_error.php');
diff --git a/tests/data/get_user.php b/tests/data/get_user.php
new file mode 100644
index 00000000..7e32d2b4
--- /dev/null
+++ b/tests/data/get_user.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStubs\WordPress\Core\Tests;
+
+use function get_user;
+use function PHPStan\Testing\assertType;
+
+assertType('WP_User|false', get_user(Faker::int()));
+assertType('WP_User|false', get_user(Faker::positiveInt()));
+assertType('WP_User|false', get_user(1));
+
+assertType('false', get_user(Faker::nonPositiveInt()));
+assertType('false', get_user(-1));
+assertType('false', get_user(0));
diff --git a/tests/data/get_user_by.php b/tests/data/get_user_by.php
new file mode 100644
index 00000000..3226ce0a
--- /dev/null
+++ b/tests/data/get_user_by.php
@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStubs\WordPress\Core\Tests;
+
+use function get_user_by;
+use function PHPStan\Testing\assertType;
+
+assertType('WP_User|false', get_user_by('id', Faker::int()));
+assertType('WP_User|false', get_user_by('id', Faker::positiveInt()));
+assertType('WP_User|false', get_user_by('id', 1));
+assertType('WP_User|false', get_user_by('ID', Faker::int()));
+assertType('WP_User|false', get_user_by('ID', Faker::positiveInt()));
+assertType('WP_User|false', get_user_by('ID', 1));
+
+assertType('false', get_user_by('id', Faker::nonPositiveInt()));
+assertType('false', get_user_by('id', -1));
+assertType('false', get_user_by('id', 0));
+assertType('false', get_user_by('ID', Faker::nonPositiveInt()));
+assertType('false', get_user_by('ID', -1));
+assertType('false', get_user_by('ID', 0));
diff --git a/wordpress-stubs.php b/wordpress-stubs.php
index dfdcb3c4..23ed71ea 100644
--- a/wordpress-stubs.php
+++ b/wordpress-stubs.php
@@ -127773,6 +127773,7 @@ function get_userdata($user_id)
      * @param string     $field The field to retrieve the user with. id | ID | slug | email | login.
      * @param int|string $value A value for $field. A user ID, slug, email address, or login name.
      * @return WP_User|false WP_User object on success, false on failure.
+     * @phpstan-return ($field is 'id'|'ID' ? ($value is int<min, 0> ? false : \WP_User|false) : \WP_User|false)
      */
     function get_user_by($field, $value)
     {
@@ -141395,6 +141396,7 @@ function delete_user_option($user_id, $option_name, $is_global = \false)
      * @param int $user_id User ID.
      *
      * @return WP_User|false WP_User object on success, false on failure.
+     * @phpstan-return ($user_id is int<min, 0> ? false : \WP_User|false)
      */
     function get_user($user_id)
     {