diff --git a/wp-includes/class-wp-block-patterns-registry.php b/wp-includes/class-wp-block-patterns-registry.php
index bfffb860d7..b7512d8121 100644
--- a/wp-includes/class-wp-block-patterns-registry.php
+++ b/wp-includes/class-wp-block-patterns-registry.php
@@ -33,7 +33,7 @@ final class WP_Block_Patterns_Registry {
 	 * @since 5.5.0
 	 *
 	 * @param string $pattern_name       Pattern name including namespace.
-	 * @param array  $pattern_properties Array containing the properties of the pattern: label, content.
+	 * @param array  $pattern_properties Array containing the properties of the pattern: title, content, description, viewportWidth, categories, keywords.
 	 * @return bool True if the pattern was registered with success and false otherwise.
 	 */
 	public function register( $pattern_name, $pattern_properties ) {
@@ -42,6 +42,16 @@ final class WP_Block_Patterns_Registry {
 			return false;
 		}
 
+		if ( ! isset( $pattern_properties['title'] ) || ! is_string( $pattern_properties['title'] ) ) {
+			_doing_it_wrong( __METHOD__, __( 'Pattern title must be a string.' ), '5.5.0' );
+			return false;
+		}
+
+		if ( ! isset( $pattern_properties['content'] ) || ! is_string( $pattern_properties['content'] ) ) {
+			_doing_it_wrong( __METHOD__, __( 'Pattern content must be a string.' ), '5.5.0' );
+			return false;
+		}
+
 		$this->registered_patterns[ $pattern_name ] = array_merge(
 			$pattern_properties,
 			array( 'name' => $pattern_name )
diff --git a/wp-includes/version.php b/wp-includes/version.php
index ce018f51fb..235db2bcd4 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-alpha-48335';
+$wp_version = '5.5-alpha-48336';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.