Index: wp-content/themes/twentythirteen/inc/back-compat.php
===================================================================
--- wp-content/themes/twentythirteen/inc/back-compat.php	(revision 36645)
+++ wp-content/themes/twentythirteen/inc/back-compat.php	(working copy)
@@ -3,8 +3,8 @@
  * Twenty Thirteen back compat functionality
  *
  * Prevents Twenty Thirteen from running on WordPress versions prior to 3.6,
- * since this theme is not meant to be backward compatible and relies on
- * many new functions and markup changes introduced in 3.6.
+ * since this theme is not meant to be backward compatible beyond that and
+ * relies on many newer functions and markup changes introduced in 3.6.
  *
  * @package WordPress
  * @subpackage Twenty_Thirteen
@@ -12,7 +12,7 @@
  */
 
 /**
- * Prevent switching to Twenty Thirteen on old versions of WordPress.
+ * Prevent switching to Twenty Thirteen on unsupported versions of WordPress.
  *
  * Switches to the default theme.
  *
@@ -29,22 +29,21 @@
  * Add message for unsuccessful theme switch.
  *
  * Prints an update nag after an unsuccessful attempt to switch to
- * Twenty Thirteen on WordPress versions prior to 3.6.
+ * Twenty Thirteen on unsupported versions of WordPress.
  *
  * @since Twenty Thirteen 1.0
  */
 function twentythirteen_upgrade_notice() {
-	$message = sprintf( __( 'Twenty Thirteen requires at least WordPress version 3.6. You are running version %s. Please upgrade and try again.', 'twentythirteen' ), $GLOBALS['wp_version'] );
-	printf( '<div class="error"><p>%s</p></div>', $message );
+	printf( '<div class="error"><p>%s</p></div>', twentythirteen_minimum_required_version_message() );
 }
 
 /**
- * Prevent the Customizer from being loaded on WordPress versions prior to 3.6.
+ * Prevent the Customizer from being loaded on unsupported versions of WordPress.
  *
  * @since Twenty Thirteen 1.0
  */
 function twentythirteen_customize() {
-	wp_die( sprintf( __( 'Twenty Thirteen requires at least WordPress version 3.6. You are running version %s. Please upgrade and try again.', 'twentythirteen' ), $GLOBALS['wp_version'] ), '', array(
+	wp_die( twentythirteen_minimum_required_version_message(), '', array(
 		'back_link' => true,
 	) );
 }
@@ -51,13 +50,30 @@
 add_action( 'load-customize.php', 'twentythirteen_customize' );
 
 /**
- * Prevent the Theme Preview from being loaded on WordPress versions prior to 3.4.
+ * Prevent the Theme Preview from being loaded on unsupported versions of WordPress.
  *
  * @since Twenty Thirteen 1.0
  */
 function twentythirteen_preview() {
 	if ( isset( $_GET['preview'] ) ) {
-		wp_die( sprintf( __( 'Twenty Thirteen requires at least WordPress version 3.6. You are running version %s. Please upgrade and try again.', 'twentythirteen' ), $GLOBALS['wp_version'] ) );
+		wp_die( twentythirteen_minimum_required_version_message() );
 	}
 }
 add_action( 'template_redirect', 'twentythirteen_preview' );
+
+/**
+ * Minimum required WordPress version message.
+ *
+ * @since Twenty Thirteen 1.9
+ *
+ * @global string $wp_version WordPress version.
+ * @return string
+ */
+function twentythirteen_minimum_required_version_message() {
+	$message = sprintf(
+		/* translators: %s: WordPress version */
+		__( 'Twenty Thirteen requires at least WordPress version 3.6. You are running version %s. Please upgrade and try again.', 'twentyfourteen' ),
+		$GLOBALS['wp_version']
+	);
+	return $message;
+}