diff --git a/man/man5/monitorix.conf.5 b/man/man5/monitorix.conf.5
index 5ab276f..55f6e84 100644
--- a/man/man5/monitorix.conf.5
+++ b/man/man5/monitorix.conf.5
@@ -1024,7 +1024,7 @@ vnet3      network    default    virtio      52:54:00:45:d0:e7
 .P
 This option also allows you to change the name that will appear in the graph, hiding the real name of the virtual machine. If no association is defined, then Monitorix will display the name specified in the \fBlist\fP option.
 .SS Processes statistics (processes.rrd)
-This graph is able to monitor an unlimited number of processes.
+This graph is able to monitor an unlimited number of processes. This graph requires a Linux kernel version 2.6.20 at least to support process I/O accounting. Some systems with older kernels might also have been ported it though.
 .P
 .BI list
 .RS