diff --git a/2011/toledo/Makefile b/2011/toledo/Makefile
index d90ea1c30..1a18a8df1 100644
--- a/2011/toledo/Makefile
+++ b/2011/toledo/Makefile
@@ -129,7 +129,7 @@ CFLAGS= ${CSTD} ${CWARN} ${ARCH} ${CDEFINE} ${CINCLUDE} ${OPT}
 #
 #LIBS=
 #LIBS= -lm
-LIBS= -L ${X11_LIBDIR} -lX11
+LIBS= -L ${X11_LIBDIR} -lX11 -lm
 #LIBS= `${SDL2_CONFIG} --libs`
 
 # C compiler to use