diff --git a/src/if_py_both.h b/src/if_py_both.h
index 3da87cc..c4d82e7 100644
--- a/src/if_py_both.h
+++ b/src/if_py_both.h
@@ -2628,7 +2628,7 @@
 	    if (li)
 		lastaddedli = li->li_prev;
 	    else
-		lastaddedli = l->lv_last;
+		lastaddedli = l->lv_u.mat.lv_last;
 	    numadded++;
 	}
 	clear_tv(&v);