diff --git a/lib/class-wp-theme-json-gutenberg.php b/lib/class-wp-theme-json-gutenberg.php
index 348e892ae3e416..cfe0c4d55ceed7 100644
--- a/lib/class-wp-theme-json-gutenberg.php
+++ b/lib/class-wp-theme-json-gutenberg.php
@@ -1744,7 +1744,7 @@ protected function get_layout_styles( $block_metadata, $types = array() ) {
 										$spacing_rule['selector']
 									);
 								} else {
-									$format          = static::ROOT_BLOCK_SELECTOR === $selector ? ':root :where(.%2$s %3$s)' : ':root :where(%1$s-%2$s %3$s)';
+									$format          = static::ROOT_BLOCK_SELECTOR === $selector ? '.%2$s %3$s' : '%1$s-%2$s %3$s';
 									$layout_selector = sprintf(
 										$format,
 										$selector,