--- rxvt-unicode/src/rxvtperl.xs	2012/12/30 11:34:13	1.209
+++ rxvt-unicode/src/rxvtperl.xs	2012/12/30 11:37:07	1.210
@@ -2208,8 +2208,8 @@
 void
 rxvt_term::set_background (rxvt_img *img, bool border = false)
 	CODE:
-        delete bg_img;
-        bg_img = 0;
+        delete THIS->bg_img;
+        THIS->bg_img = 0;
         THIS->bg_flags &= ~(rxvt_term::BG_NEEDS_REFRESH | rxvt_term::BG_INHIBIT_RENDER | rxvt_term::BG_IS_TRANSPARENT);
 
         if (img) // TODO: cannot be false