diff --git a/tests/phpunit/tests/customize/setting.php b/tests/phpunit/tests/customize/setting.php
index 9db91a60e8..3ee1a8c53f 100644
--- a/tests/phpunit/tests/customize/setting.php
+++ b/tests/phpunit/tests/customize/setting.php
@@ -48,6 +48,46 @@ class Tests_WP_Customize_Setting extends WP_UnitTestCase {
 		$this->assertEquals( false, $setting->dirty );
 	}
 
+	/**
+	 * A test validate callback function.
+	 *
+	 * @param mixed                $value   The setting value.
+	 * @param WP_Customize_Setting $setting The setting object.
+	 */
+	public function validate_callback_for_tests( $value, $setting ) {
+		return $value . ':validate_callback';
+	}
+
+	/**
+	 * A test sanitize callback function.
+	 *
+	 * @param mixed                $value   The setting value.
+	 * @param WP_Customize_Setting $setting The setting object.
+	 */
+	public function sanitize_callback_for_tests( $value, $setting ) {
+		return $value . ':sanitize_callback';
+	}
+
+	/**
+	 * A test sanitize JS callback function.
+	 *
+	 * @param mixed                $value   The setting value.
+	 * @param WP_Customize_Setting $setting The setting object.
+	 */
+	public function sanitize_js_callback_for_tests( $value, $setting ) {
+		return $value . ':sanitize_js_callback';
+	}
+
+	/**
+	 * Sanitize JS callback for base64 encoding.
+	 *
+	 * @param mixed                $value   The setting value.
+	 * @param WP_Customize_Setting $setting The setting object.
+	 */
+	function sanitize_js_callback_base64_for_testing( $value, $setting ) {
+		return base64_encode( $value );
+	}
+
 	function test_constructor_with_args() {
 		$args = array(
 			'type' => 'option',
@@ -55,9 +95,9 @@ class Tests_WP_Customize_Setting extends WP_UnitTestCase {
 			'theme_supports' => 'widgets',
 			'default' => 'barbar',
 			'transport' => 'postMessage',
-			'validate_callback' => create_function( '$value', 'return $value . ":validate_callback";' ),
-			'sanitize_callback' => create_function( '$value', 'return $value . ":sanitize_callback";' ),
-			'sanitize_js_callback' => create_function( '$value', 'return $value . ":sanitize_js_callback";' ),
+			'validate_callback' => array( $this, 'validate_callback_for_tests' ),
+			'sanitize_callback' => array( $this, 'sanitize_callback_for_tests' ),
+			'sanitize_js_callback' => array( $this, 'sanitize_js_callback_for_tests' ),
 		);
 		$setting = new WP_Customize_Setting( $this->manager, 'bar', $args );
 		$this->assertEquals( 'bar', $setting->id );
@@ -615,7 +655,7 @@ class Tests_WP_Customize_Setting extends WP_UnitTestCase {
 			'default' => $default,
 			'transport' => 'postMessage',
 			'dirty' => true,
-			'sanitize_js_callback' => create_function( '$value', 'return base64_encode( $value );' ),
+			'sanitize_js_callback' => array( $this, 'sanitize_js_callback_base64_for_testing' ),
 		);
 		$setting = new WP_Customize_Setting( $this->manager, 'name', $args );
 
diff --git a/tests/phpunit/tests/image/editor.php b/tests/phpunit/tests/image/editor.php
index 1a8fbeb8e8..3eac487164 100644
--- a/tests/phpunit/tests/image/editor.php
+++ b/tests/phpunit/tests/image/editor.php
@@ -45,6 +45,20 @@ class Tests_Image_Editor extends WP_Image_UnitTestCase {
 		WP_Image_Editor_Mock::$load_return = true;
 	}
 
+	/**
+	 * Return integer of 95 for testing.
+	 */
+	public function return_integer_95() {
+		return 95;
+	}
+
+	/**
+	 * Return integer of 100 for testing.
+	 */
+	public function return_integer_100() {
+		return 100;
+	}
+
 	/**
 	 * Test test_quality
 	 * @ticket 6821
@@ -59,11 +73,11 @@ class Tests_Image_Editor extends WP_Image_UnitTestCase {
 		$this->assertEquals( 82, $editor->get_quality() );
 
 		// Ensure the quality filters do not have precedence if created after editor instantiation.
-		$func_100_percent = create_function( '', "return 100;" );
+		$func_100_percent = array( $this, 'return_integer_100' );
 		add_filter( 'wp_editor_set_quality', $func_100_percent );
 		$this->assertEquals( 82, $editor->get_quality() );
 
-		$func_95_percent = create_function( '', "return 95;" );
+		$func_95_percent = array( $this, 'return_integer_95' );
 		add_filter( 'jpeg_quality', $func_95_percent );
 		$this->assertEquals( 82, $editor->get_quality() );