diff -up crystal-stacker-1.5/cs/source/Makefile.unix~ crystal-stacker-1.5/cs/source/Makefile.unix

--- crystal-stacker-1.5/cs/source/Makefile.unix~	2006-04-07 10:32:26.000000000 +0200

+++ crystal-stacker-1.5/cs/source/Makefile.unix	2010-02-15 09:27:12.971926372 +0100

@@ -1,7 +1,7 @@

 PREFIX  = /usr/local

 DATADIR = $(PREFIX)/share/$(TARGET)

 CFLAGS  = -g -Wall -O2 -fsigned-char

-LDFLAGS = `allegro-config --libs` -laldmb -ldumb

+LDFLAGS = `allegro-config --libs` -laldmb -ldumb -lpthread

 DEFINES = -DDATADIR=\"$(DATADIR)/\"

 OBJS    =    animate.o  misc.o   cs2bd.o     cs2ns.o    game.o      keys.o   \

   battle.o   cs.o       cs2bl.o  draw.o      gef.o      logo.o      mywav.o  \