diff --git a/lib/compat/wordpress-6.1/theme.php b/lib/compat/wordpress-6.1/theme.php
index 441fc63071436..4787f1057b474 100644
--- a/lib/compat/wordpress-6.1/theme.php
+++ b/lib/compat/wordpress-6.1/theme.php
@@ -29,3 +29,19 @@ function gutenberg_create_initial_theme_features() {
 	);
 }
 add_action( 'setup_theme', 'gutenberg_create_initial_theme_features', 0 );
+
+if ( ! function_exists( 'wp_theme_element_class_name' ) ) {
+	/**
+	 * Given an element name, returns a class name.
+	 * Alias from WP_Theme_JSON_Gutenberg::get_element_class_name.
+	 *
+	 * @param string $element The name of the element.
+	 *
+	 * @return string The name of the class.
+	 *
+	 * @since 6.1.0
+	 */
+	function wp_theme_element_class_name( $element ) {
+		return WP_Theme_JSON_Gutenberg::get_element_class_name( $element );
+	}
+}
diff --git a/packages/block-library/src/comments/index.php b/packages/block-library/src/comments/index.php
index 14fe6355a11a7..edc1bedab083f 100644
--- a/packages/block-library/src/comments/index.php
+++ b/packages/block-library/src/comments/index.php
@@ -109,7 +109,7 @@ function register_block_core_comments() {
  */
 function comments_block_form_defaults( $fields ) {
 	if ( wp_is_block_theme() ) {
-		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s wp-block-button__link ' . WP_Theme_JSON_Gutenberg::get_element_class_name( 'button' ) . '" value="%4$s" />';
+		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="%3$s wp-block-button__link ' . wp_theme_element_class_name( 'button' ) . '" value="%4$s" />';
 		$fields['submit_field']  = '<p class="form-submit wp-block-button">%1$s %2$s</p>';
 	}
 
diff --git a/packages/block-library/src/post-comments-form/index.php b/packages/block-library/src/post-comments-form/index.php
index 40dad1a530495..4bbd24b245411 100644
--- a/packages/block-library/src/post-comments-form/index.php
+++ b/packages/block-library/src/post-comments-form/index.php
@@ -72,7 +72,7 @@ function register_block_core_post_comments_form() {
  */
 function post_comments_form_block_form_defaults( $fields ) {
 	if ( wp_is_block_theme() ) {
-		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="wp-block-button__link ' . WP_Theme_JSON_Gutenberg::get_element_class_name( 'button' ) . '" value="%4$s" />';
+		$fields['submit_button'] = '<input name="%1$s" type="submit" id="%2$s" class="wp-block-button__link ' . wp_theme_element_class_name( 'button' ) . '" value="%4$s" />';
 		$fields['submit_field']  = '<p class="form-submit wp-block-button">%1$s %2$s</p>';
 	}
 
diff --git a/packages/block-library/src/search/index.php b/packages/block-library/src/search/index.php
index 8e2a158969acb..40cf5fcf5478f 100644
--- a/packages/block-library/src/search/index.php
+++ b/packages/block-library/src/search/index.php
@@ -121,7 +121,7 @@ function render_block_core_search( $attributes ) {
 		}
 
 		// Include the button element class.
-		$button_classes[] = WP_Theme_JSON_Gutenberg::get_element_class_name( 'button' );
+		$button_classes[] = wp_theme_element_class_name( 'button' );
 		$button_markup    = sprintf(
 			'<button type="submit" class="%s" %s %s>%s</button>',
 			esc_attr( implode( ' ', $button_classes ) ),
diff --git a/phpunit/class-wp-theme-json-test.php b/phpunit/class-wp-theme-json-test.php
index 42146c66e6635..35c4bf153ddb2 100644
--- a/phpunit/class-wp-theme-json-test.php
+++ b/phpunit/class-wp-theme-json-test.php
@@ -797,14 +797,14 @@ function test_remove_invalid_element_pseudo_selectors() {
 
 	function test_get_element_class_name_button() {
 		$expected = 'wp-element-button';
-		$actual   = WP_Theme_JSON_Gutenberg::get_element_class_name( 'button' );
+		$actual   = wp_theme_element_class_name( 'button' );
 
 		$this->assertEquals( $expected, $actual );
 	}
 
 	function test_get_element_class_name_invalid() {
 		$expected = '';
-		$actual   = WP_Theme_JSON_Gutenberg::get_element_class_name( 'unknown-element' );
+		$actual   = wp_theme_element_class_name( 'unknown-element' );
 
 		$this->assertEquals( $expected, $actual );
 	}