Index: trunk/src/change_act.c
===================================================================
--- trunk/src/change_act.c	(revision 36472)
+++ trunk/src/change_act.c	(revision 36473)
@@ -676,7 +676,7 @@
 	RND_ACT_CONVARG(2, FGW_STR, SetThermal, style = argv[2].val.str);
 
 	if (function && *function && style && *style) {
-		rnd_bool absolute;
+		rnd_bool absolute = 1;
 
 		if (rnd_strcasecmp(style, "noshape") == 0)
 			kind = PCB_THERMAL_NOSHAPE | PCB_THERMAL_ON;