diff --git tests/phpunit/tests/link/themeFile.php tests/phpunit/tests/link/themeFile.php
index fe0dbcf..2af10cc 100644
--- tests/phpunit/tests/link/themeFile.php
+++ tests/phpunit/tests/link/themeFile.php
@@ -102,10 +102,13 @@ class Test_Theme_File extends WP_UnitTestCase {
 
 	/**
 	 * @ticket 18302
+	 * @ticket 43663
 	 *
 	 * @dataProvider data_theme_files
 	 */
-	public function test_theme_file_uri_returns_valid_uri( $file, $expected_theme, $existence ) {
+	public function test_theme_file_uri_returns_valid_uri( $file, $expected_theme, $existence ) {		
+		switch_theme( $expected_theme );
+		
 		$uri        = get_theme_file_uri( $file );
 		$parent_uri = get_parent_theme_file_uri( $file );