diff --git a/tests/phpunit/tests/theme/wpThemeJson.php b/tests/phpunit/tests/theme/wpThemeJson.php
index 68da3285602e7..394f4e8d0bc0b 100644
--- a/tests/phpunit/tests/theme/wpThemeJson.php
+++ b/tests/phpunit/tests/theme/wpThemeJson.php
@@ -4434,10 +4434,10 @@ public function test_set_spacing_sizes( $spacing_scale, $expected_output ) {
 						'spacingScale' => $spacing_scale,
 					),
 				),
-			)
+			),
+			'default'
 		);
 
-		$theme_json->set_spacing_sizes();
 		$this->assertSame( $expected_output, _wp_array_get( $theme_json->get_raw_data(), array( 'settings', 'spacing', 'spacingSizes', 'default' ) ) );
 	}
 
@@ -4720,17 +4720,6 @@ public function test_set_spacing_sizes_when_invalid( $spacing_scale, $expected_o
 		$this->expectException( Exception::class );
 		$this->expectExceptionMessage( 'Some of the theme.json settings.spacing.spacingScale values are invalid' );
 
-		$theme_json = new WP_Theme_JSON(
-			array(
-				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
-				'settings' => array(
-					'spacing' => array(
-						'spacingScale' => $spacing_scale,
-					),
-				),
-			)
-		);
-
 		// Ensure PHPUnit 10 compatibility.
 		set_error_handler(
 			static function ( $errno, $errstr ) {
@@ -4740,7 +4729,17 @@ static function ( $errno, $errstr ) {
 			E_ALL
 		);
 
-		$theme_json->set_spacing_sizes();
+		$theme_json = new WP_Theme_JSON(
+			array(
+				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
+				'settings' => array(
+					'spacing' => array(
+						'spacingScale' => $spacing_scale,
+					),
+				),
+			),
+			'default'
+		);
 
 		restore_error_handler();