diff --git a/src/wp-admin/includes/post.php b/src/wp-admin/includes/post.php
index a4dd6a0519..51af5bb2f2 100644
--- a/src/wp-admin/includes/post.php
+++ b/src/wp-admin/includes/post.php
@@ -2147,76 +2147,6 @@ function taxonomy_meta_box_sanitize_cb_input( $taxonomy, $terms ) {
 	return $clean_terms;
 }
 
-/**
- * Returns whether the post can be edited in the block editor.
- *
- * @since 5.0.0
- *
- * @param int|WP_Post $post Post ID or WP_Post object.
- * @return bool Whether the post can be edited in the block editor.
- */
-function use_block_editor_for_post( $post ) {
-	$post = get_post( $post );
-
-	if ( ! $post ) {
-		return false;
-	}
-
-	// We're in the meta box loader, so don't use the block editor.
-	if ( isset( $_GET['meta-box-loader'] ) ) {
-		check_admin_referer( 'meta-box-loader', 'meta-box-loader-nonce' );
-		return false;
-	}
-
-	$use_block_editor = use_block_editor_for_post_type( $post->post_type );
-
-	/**
-	 * Filters whether a post is able to be edited in the block editor.
-	 *
-	 * @since 5.0.0
-	 *
-	 * @param bool    $use_block_editor Whether the post can be edited or not.
-	 * @param WP_Post $post             The post being checked.
-	 */
-	return apply_filters( 'use_block_editor_for_post', $use_block_editor, $post );
-}
-
-/**
- * Returns whether a post type is compatible with the block editor.
- *
- * The block editor depends on the REST API, and if the post type is not shown in the
- * REST API, then it won't work with the block editor.
- *
- * @since 5.0.0
- *
- * @param string $post_type The post type.
- * @return bool Whether the post type can be edited with the block editor.
- */
-function use_block_editor_for_post_type( $post_type ) {
-	if ( ! post_type_exists( $post_type ) ) {
-		return false;
-	}
-
-	if ( ! post_type_supports( $post_type, 'editor' ) ) {
-		return false;
-	}
-
-	$post_type_object = get_post_type_object( $post_type );
-	if ( $post_type_object && ! $post_type_object->show_in_rest ) {
-		return false;
-	}
-
-	/**
-	 * Filters whether a post is able to be edited in the block editor.
-	 *
-	 * @since 5.0.0
-	 *
-	 * @param bool   $use_block_editor  Whether the post type can be edited or not. Default true.
-	 * @param string $post_type         The post type being checked.
-	 */
-	return apply_filters( 'use_block_editor_for_post_type', true, $post_type );
-}
-
 /**
  * Prepares server-registered blocks for the block editor.
  *
diff --git a/src/wp-includes/post.php b/src/wp-includes/post.php
index 23719feadd..05b97d699f 100644
--- a/src/wp-includes/post.php
+++ b/src/wp-includes/post.php
@@ -8106,3 +8106,75 @@ function wp_get_original_image_url( $attachment_id ) {
 function wp_untrash_post_set_previous_status( $new_status, $post_id, $previous_status ) {
 	return $previous_status;
 }
+
+/**
+ * Returns whether the post can be edited in the block editor.
+ *
+ * @since 5.0.0
+ * @since 6.1.0 Moved to wp-includes from wp-admin.
+ *
+ * @param int|WP_Post $post Post ID or WP_Post object.
+ * @return bool Whether the post can be edited in the block editor.
+ */
+function use_block_editor_for_post( $post ) {
+	$post = get_post( $post );
+
+	if ( ! $post ) {
+		return false;
+	}
+
+	// We're in the meta box loader, so don't use the block editor.
+	if ( is_admin() && isset( $_GET['meta-box-loader'] ) ) {
+		check_admin_referer( 'meta-box-loader', 'meta-box-loader-nonce' );
+		return false;
+	}
+
+	$use_block_editor = use_block_editor_for_post_type( $post->post_type );
+
+	/**
+	 * Filters whether a post is able to be edited in the block editor.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param bool    $use_block_editor Whether the post can be edited or not.
+	 * @param WP_Post $post             The post being checked.
+	 */
+	return apply_filters( 'use_block_editor_for_post', $use_block_editor, $post );
+}
+
+/**
+ * Returns whether a post type is compatible with the block editor.
+ *
+ * The block editor depends on the REST API, and if the post type is not shown in the
+ * REST API, then it won't work with the block editor.
+ *
+ * @since 5.0.0
+ * @since 6.1.0 Moved to wp-includes from wp-admin.
+ *
+ * @param string $post_type The post type.
+ * @return bool Whether the post type can be edited with the block editor.
+ */
+function use_block_editor_for_post_type( $post_type ) {
+	if ( ! post_type_exists( $post_type ) ) {
+		return false;
+	}
+
+	if ( ! post_type_supports( $post_type, 'editor' ) ) {
+		return false;
+	}
+
+	$post_type_object = get_post_type_object( $post_type );
+	if ( $post_type_object && ! $post_type_object->show_in_rest ) {
+		return false;
+	}
+
+	/**
+	 * Filters whether a post is able to be edited in the block editor.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param bool   $use_block_editor  Whether the post type can be edited or not. Default true.
+	 * @param string $post_type         The post type being checked.
+	 */
+	return apply_filters( 'use_block_editor_for_post_type', true, $post_type );
+}
diff --git a/tests/phpunit/tests/admin/includesPost.php b/tests/phpunit/tests/admin/includesPost.php
index d27f68255e..d6ae09a302 100644
--- a/tests/phpunit/tests/admin/includesPost.php
+++ b/tests/phpunit/tests/admin/includesPost.php
@@ -789,39 +789,6 @@ class Tests_Admin_IncludesPost extends WP_UnitTestCase {
 		$this->assertSame( $p, post_exists( $title, $content, $date ) );
 	}
 
-	public function test_use_block_editor_for_post() {
-		$this->assertFalse( use_block_editor_for_post( -1 ) );
-		$bogus_post_id = $this->factory()->post->create(
-			array(
-				'post_type' => 'bogus',
-			)
-		);
-		$this->assertFalse( use_block_editor_for_post( $bogus_post_id ) );
-
-		register_post_type(
-			'restless',
-			array(
-				'show_in_rest' => false,
-			)
-		);
-		$restless_post_id = $this->factory()->post->create(
-			array(
-				'post_type' => 'restless',
-			)
-		);
-		$this->assertFalse( use_block_editor_for_post( $restless_post_id ) );
-
-		$generic_post_id = $this->factory()->post->create();
-
-		add_filter( 'use_block_editor_for_post', '__return_false' );
-		$this->assertFalse( use_block_editor_for_post( $generic_post_id ) );
-		remove_filter( 'use_block_editor_for_post', '__return_false' );
-
-		add_filter( 'use_block_editor_for_post', '__return_true' );
-		$this->assertTrue( use_block_editor_for_post( $restless_post_id ) );
-		remove_filter( 'use_block_editor_for_post', '__return_true' );
-	}
-
 	public function test_get_block_editor_server_block_settings() {
 		$name     = 'core/test';
 		$settings = array(
diff --git a/tests/phpunit/tests/post.php b/tests/phpunit/tests/post.php
index 8180a867dc..108e6ef4a6 100644
--- a/tests/phpunit/tests/post.php
+++ b/tests/phpunit/tests/post.php
@@ -1844,4 +1844,43 @@ class Tests_Post extends WP_UnitTestCase {
 		unstick_post( 3 );
 		$this->assertSameSets( array( 1, 2, 2 ), get_option( 'sticky_posts' ) );
 	}
+
+	/**
+	 * Check if post supports block editor.
+	 *
+	 * @ticket 51819
+	 * @covers ::use_block_editor_for_post
+	 */
+	public function test_use_block_editor_for_post() {
+		$this->assertFalse( use_block_editor_for_post( -1 ) );
+		$bogus_post_id = $this->factory()->post->create(
+			array(
+				'post_type' => 'bogus',
+			)
+		);
+		$this->assertFalse( use_block_editor_for_post( $bogus_post_id ) );
+
+		register_post_type(
+			'restless',
+			array(
+				'show_in_rest' => false,
+			)
+		);
+		$restless_post_id = $this->factory()->post->create(
+			array(
+				'post_type' => 'restless',
+			)
+		);
+		$this->assertFalse( use_block_editor_for_post( $restless_post_id ) );
+
+		$generic_post_id = $this->factory()->post->create();
+
+		add_filter( 'use_block_editor_for_post', '__return_false' );
+		$this->assertFalse( use_block_editor_for_post( $generic_post_id ) );
+		remove_filter( 'use_block_editor_for_post', '__return_false' );
+
+		add_filter( 'use_block_editor_for_post', '__return_true' );
+		$this->assertTrue( use_block_editor_for_post( $restless_post_id ) );
+		remove_filter( 'use_block_editor_for_post', '__return_true' );
+	}
 }