diff --git a/README.md b/README.md
index a11725f..1db8118 100644
--- a/README.md
+++ b/README.md
@@ -102,7 +102,7 @@ rrdtool update cpu.rrd $(date +%s):$(LANG=C sar -u ALL 0 -1 |tail -n1 |awk '{pri
 Dans un `while true; do …; sleep 60; done`
 
 ```
-rrdtool graph cpu-daily.png  --end now --start end-86400s \
+rrdtool graph cpu-daily.svg --imgformat SVG --end now --start end-86400s \
 	DEF:user=cpu.rrd:user:AVERAGE \
 	DEF:nice=cpu.rrd:nice:AVERAGE \
 	DEF:sys=cpu.rrd:sys:AVERAGE \