--- Makefile.old	2011-06-20 20:49:09.928013768 +0200
+++ Makefile	2011-06-20 20:49:18.725566328 +0200
@@ -3,7 +3,7 @@
 #
 
 sources = game.c main.c road.c map.c gfx.c
-libs = `sdl-config --libs`
+libs = `sdl-config --libs` -lm
 cflags = -O2 -Wall `sdl-config --cflags`
 version = 0.9
 bdir = /tmp/trailblazer-$(version)