--- Gtk/Makefile	2005-07-26 12:03:44.000000000 +0200
+++ Gtk1/Makefile	2012-05-18 00:22:20.883487513 +0200
@@ -69,7 +69,7 @@
 
 #######################################################################
 
-LIBS = $(GTK_LIBS) $(SOUND_LIBS)
+LIBS = $(GTK_LIBS) $(SOUND_LIBS) -lm
 
 gtkmagnetic: $(OBJS)
 	$(CC) -o gtkmagnetic $(OBJS) $(LIBS)