--- a/src/Makefile.am	2011-06-10 11:32:03.905618275 +0200
+++ b/src/Makefile.am	2011-06-10 11:32:15.539347083 +0200
@@ -42,7 +42,7 @@
 heroeslvl_SOURCES = heroeslvl.c
 
 heroes_LDADD = lvl/libhlvl.a media/libhmcommon.a ../lib/libheroes.a \
-	       $(INTLLIBS) $(LIBALT_LOCAL_XLDADD) $(LIBALT_XLDADD)
+	       $(INTLLIBS) $(LIBALT_LOCAL_XLDADD) $(LIBALT_XLDADD) -lm
 heroes_LDFLAGS = $(LIBALT_XLDFLAGS)
 
 ## Depend upon Makefile because the value of LIBALT_LOCAL_LDADD might