Index: wp-content/themes/twentythirteen/inc/custom-header.php
===================================================================
--- wp-content/themes/twentythirteen/inc/custom-header.php	(revision 24974)
+++ wp-content/themes/twentythirteen/inc/custom-header.php	(working copy)
@@ -59,7 +59,7 @@
 		),
 	) );
 }
-add_action( 'after_setup_theme', 'twentythirteen_custom_header_setup' );
+add_action( 'after_setup_theme', 'twentythirteen_custom_header_setup', 11 );
 
 /**
  * Loads our special font CSS files.