diff --git a/functionMap.php b/functionMap.php
index 6c2805d..67590fe 100644
--- a/functionMap.php
+++ b/functionMap.php
@@ -133,7 +133,7 @@
     'rest_ensure_response' => ['($response is \WP_Error ? \WP_Error : \WP_REST_Response)'],
     'sanitize_bookmark_field' => ['array<int, int>|int|string', 'field' => "'link_id'|'link_url'|'link_name'|'link_image'|'link_target'|'link_description'|'link_visible'|'link_owner'|'link_rating'|'link_updated'|'link_rel'|'link_notes'|'link_rss'|'link_category'"],
     'sanitize_category' => ['T', '@phpstan-template' => 'T of array|object', 'category' => 'T'],
-    'sanitize_post' => ['T', '@phpstan-template' => 'T of array|object', 'post' => 'T'],
+    'sanitize_post' => ['(T is \WP_Post ? \WP_Post : (T is object ? object : (T is array ? array : T)))', '@phpstan-template T' => 'of mixed', 'post' => 'T'],
     'sanitize_sql_orderby' => ['(T is non-falsy-string ? T|false : false)', '@phpstan-template T' => 'of string', 'orderby' => 'T'],
     'sanitize_term' => ['T', '@phpstan-template' => 'T of array|object', 'term' => 'T'],
     'sanitize_title_with_dashes' => ['lowercase-string', 'context' => "'display'|'save'"],
diff --git a/tests/data/return/sanitize-post.php b/tests/data/return/sanitize-post.php
new file mode 100644
index 0000000..c28f81b
--- /dev/null
+++ b/tests/data/return/sanitize-post.php
@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStubs\WordPress\Core\Tests;
+
+use stdClass;
+
+use function sanitize_post;
+use function PHPStan\Testing\assertType;
+
+assertType('WP_Post', sanitize_post(Faker::wpPost(), Faker::string()));
+assertType('object', sanitize_post(Faker::object(), Faker::string()));
+assertType('object', sanitize_post(new stdClass(), Faker::string()));
+assertType('array', sanitize_post(Faker::array(), Faker::string()));
+assertType('array', sanitize_post(Faker::strArray(), Faker::string()));
+assertType('array', sanitize_post(Faker::intArray(), Faker::string()));
+assertType('array', sanitize_post(Faker::array(Faker::string()), Faker::string()));
+
+// Incorrect type of $post is returned as-is.
+assertType("'foo'", sanitize_post('foo', Faker::string()));
+assertType('123', sanitize_post(123, Faker::string()));
+assertType('string', sanitize_post(Faker::string(), Faker::string()));
+assertType('int', sanitize_post(Faker::int(), Faker::string()));
+assertType('bool', sanitize_post(Faker::bool(), Faker::string()));
diff --git a/wordpress-stubs.php b/wordpress-stubs.php
index 86d48f7..4d26496 100644
--- a/wordpress-stubs.php
+++ b/wordpress-stubs.php
@@ -132335,9 +132335,9 @@ function is_sticky($post_id = 0)
      * @return object|WP_Post|array The now sanitized post object or array (will be the
      *                              same type as `$post`).
      * @phpstan-param 'raw'|'edit'|'db'|'display'|'attribute'|'js' $context
-     * @phpstan-template T of array|object
+     * @phpstan-template T of mixed
      * @phpstan-param T $post
-     * @phpstan-return T
+     * @phpstan-return (T is \WP_Post ? \WP_Post : (T is object ? object : (T is array ? array : T)))
      */
     function sanitize_post($post, $context = 'display')
     {