diff --git a/Makefile b/Makefile
index 3664edf..af7463a 100644
--- a/Makefile
+++ b/Makefile
@@ -91,8 +91,8 @@ update_net: net.rrd
 
 disk.rrd:
 	rrdtool create $@ --start $$(( $(NOW) - 1 )) --step $(STEP) --no-overwrite \
-		DS:mbfsfree:COUNTER:120:0:U \
-		DS:mbfsused:COUNTER:120:0:U \
+		DS:mbfsfree:GAUGE:120:0:U \
+		DS:mbfsused:GAUGE:120:0:U \
 		RRA:LAST:0.5:1:1440 \
 		RRA:AVERAGE:0.5:420:1440 \
 		RRA:AVERAGE:0.5:1860:1440 \