diff --git a/src/wp-includes/block-supports/typography.php b/src/wp-includes/block-supports/typography.php
index bd91bcfe76..9d947088e2 100644
--- a/src/wp-includes/block-supports/typography.php
+++ b/src/wp-includes/block-supports/typography.php
@@ -57,6 +57,12 @@ function wp_register_typography_support( $block_type ) {
 			'type' => 'string',
 		);
 	}
+
+	if ( $has_font_family_support && ! array_key_exists( 'fontFamily', $block_type->attributes ) ) {
+		$block_type->attributes['fontFamily'] = array(
+			'type' => 'string',
+		);
+	}
 }
 
 /**