diff --git a/src/wp-includes/class-wp-post.php b/src/wp-includes/class-wp-post.php
index 4f85f1280c..654dd05bfa 100644
--- a/src/wp-includes/class-wp-post.php
+++ b/src/wp-includes/class-wp-post.php
@@ -247,7 +247,7 @@ final class WP_Post {
 
 			$_post = sanitize_post( $_post, 'raw' );
 			wp_cache_add( $_post->ID, $_post, 'posts' );
-		} elseif ( empty( $_post->filter ) ) {
+		} elseif ( empty( $_post->filter ) || 'raw' !== $_post->filter ) {
 			$_post = sanitize_post( $_post, 'raw' );
 		}
 
diff --git a/src/wp-includes/post.php b/src/wp-includes/post.php
index 3906e21f7c..182031cf99 100644
--- a/src/wp-includes/post.php
+++ b/src/wp-includes/post.php
@@ -7374,6 +7374,9 @@ function update_post_cache( &$posts ) {
 
 	$data = array();
 	foreach ( $posts as $post ) {
+		if ( empty( $post->filter ) || 'raw' !== $post->filter ) {
+			$post = sanitize_post( $post, 'raw' );
+		}
 		$data[ $post->ID ] = $post;
 	}
 	wp_cache_add_multiple( $data, 'posts' );
diff --git a/tests/phpunit/tests/post/updatePostCache.php b/tests/phpunit/tests/post/updatePostCache.php
new file mode 100644
index 0000000000..976f7af118
--- /dev/null
+++ b/tests/phpunit/tests/post/updatePostCache.php
@@ -0,0 +1,141 @@
+<?php
+/**
+ * Test `wp_update_cache()`.
+ *
+ * @package WordPress
+ */
+
+/**
+ * Test class for `wp_update_cache()`.
+ *
+ * @group post
+ * @group query
+ *
+ * @covers ::update_post_cache
+ */
+class Tests_Post_UpdatePostCache extends WP_UnitTestCase {
+
+	/**
+	 * Post IDs from the shared fixture.
+	 *
+	 * @var array
+	 */
+	public static $post_ids;
+
+	/**
+	 * Set up test resources before the class.
+	 *
+	 * @param WP_UnitTest_Factory $factory The unit test factory.
+	 */
+	public static function wpSetupBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$post_ids = $factory->post->create_many( 1 );
+	}
+
+	/**
+	 * Ensure that `update_post_cache()` returns `null` when
+	 * `$posts` is empty.
+	 *
+	 * @ticket 50567
+	 */
+	public function test_should_return_null_with_an_empty_array() {
+		$posts = array();
+		$this->assertNull( update_post_cache( $posts ) );
+	}
+
+	/**
+	 * Ensure filter = raw is always set via Query.
+	 *
+	 * @ticket 50567
+	 */
+	public function test_query_caches_post_filter() {
+		$post_id = self::$post_ids[0];
+		$this->go_to( '/' );
+
+		$cached_post = wp_cache_get( $post_id, 'posts' );
+		$this->assertIsObject(
+			$cached_post,
+			'The cached post is not an object'
+		);
+
+		$this->assertObjectHasAttribute(
+			'filter',
+			$cached_post,
+			'The cached post does not have a "filter" property'
+		);
+
+		$this->assertSame(
+			'raw',
+			$cached_post->filter,
+			'The filter is not set to "raw"'
+		);
+	}
+
+	/**
+	 * Ensure filter = raw is always set via get_post.
+	 *
+	 * @ticket 50567
+	 */
+	public function test_get_post_caches_post_filter() {
+		$post_id = self::$post_ids[0];
+		get_post( $post_id );
+
+		$cached_post = wp_cache_get( $post_id, 'posts' );
+		$this->assertSame( 'raw', $cached_post->filter );
+	}
+
+	/**
+	 * Ensure filter = raw is always set via get_post called with a different filter setting.
+	 *
+	 * @ticket 50567
+	 */
+	public function test_get_post_caches_post_filter_is_always_raw() {
+		$post_id = self::$post_ids[0];
+		get_post( $post_id, OBJECT, 'display' );
+
+		$cached_post = wp_cache_get( $post_id, 'posts' );
+		$this->assertIsObject(
+			$cached_post,
+			'The cached post is not an object'
+		);
+
+		$this->assertObjectHasAttribute(
+			'filter',
+			$cached_post,
+			'The cached post does not have a "filter" property'
+		);
+
+		$this->assertSame(
+			'raw',
+			$cached_post->filter,
+			'The filter is not set to "raw"'
+		);
+	}
+
+	/**
+	 * Ensure filter = raw is always set via get_posts.
+	 *
+	 * @ticket 50567
+	 */
+	public function test_get_posts_caches_post_filter_is_always_raw() {
+		$post_id = self::$post_ids[0];
+		get_posts( array( 'includes' => $post_id ) );
+
+		$cached_post = wp_cache_get( $post_id, 'posts' );
+		$this->assertIsObject(
+			$cached_post,
+			'The cached post is not an object'
+		);
+
+		$this->assertObjectHasAttribute(
+			'filter',
+			$cached_post,
+			'The cached post does not have a "filter" property'
+		);
+
+		$this->assertSame(
+			'raw',
+			$cached_post->filter,
+			'The filter is not set to "raw"'
+		);
+	}
+}