diff --git a/lib/class-wp-theme-json-gutenberg.php b/lib/class-wp-theme-json-gutenberg.php
index 1dec7b164d880..e0d3ff09861d5 100644
--- a/lib/class-wp-theme-json-gutenberg.php
+++ b/lib/class-wp-theme-json-gutenberg.php
@@ -2745,7 +2745,7 @@ static function ( $pseudo_selector ) use ( $selector ) {
 		}
 
 		// 2. Generate and append the rules that use the general selector.
-		$block_rules .= static::to_ruleset( ":where($selector)", $declarations );
+		$block_rules .= static::to_ruleset( ":root :where($selector)", $declarations );
 
 		// 3. Generate and append the rules that use the duotone selector.
 		if ( isset( $block_metadata['duotone'] ) && ! empty( $declarations_duotone ) ) {
@@ -2762,7 +2762,7 @@ static function ( $pseudo_selector ) use ( $selector ) {
 
 		// 5. Generate and append the feature level rulesets.
 		foreach ( $feature_declarations as $feature_selector => $individual_feature_declarations ) {
-			$block_rules .= static::to_ruleset( ":where($feature_selector)", $individual_feature_declarations );
+			$block_rules .= static::to_ruleset( ":root :where($feature_selector)", $individual_feature_declarations );
 		}
 
 		// 6. Generate and append the style variation rulesets.
diff --git a/packages/block-editor/src/components/global-styles/use-global-styles-output.js b/packages/block-editor/src/components/global-styles/use-global-styles-output.js
index 23bb88efc9991..ba06b4caf4e02 100644
--- a/packages/block-editor/src/components/global-styles/use-global-styles-output.js
+++ b/packages/block-editor/src/components/global-styles/use-global-styles-output.js
@@ -861,7 +861,7 @@ export const toStyles = (
 						( [ cssSelector, declarations ] ) => {
 							if ( declarations.length ) {
 								const rules = declarations.join( ';' );
-								ruleset += `:where(${ cssSelector }){${ rules };}`;
+								ruleset += `:root :where(${ cssSelector }){${ rules };}`;
 							}
 						}
 					);
@@ -956,7 +956,7 @@ export const toStyles = (
 					isTemplate
 				);
 				if ( declarations?.length ) {
-					ruleset += `:where(${ selector }){${ declarations.join(
+					ruleset += `:root :where(${ selector }){${ declarations.join(
 						';'
 					) };}`;
 				}