diff --git a/metricbeat/module/system/process/process.go b/metricbeat/module/system/process/process.go
index c1dd2b1017f7..978dc6827de0 100644
--- a/metricbeat/module/system/process/process.go
+++ b/metricbeat/module/system/process/process.go
@@ -45,7 +45,6 @@ func init() {
 type MetricSet struct {
 	mb.BaseMetricSet
 	stats  *process.Stats
-	cgroup *cgroup.Reader
 	perCPU bool
 	setpid int
 }
@@ -66,6 +65,10 @@ func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
 		}
 	}
 
+	if config.Pid != 0 && config.Procs[0] != ".*" {
+		logp.L().Warnf("`processes.pid` set to %d, but `processes` is set to a non-default value. Metricset will only report metrics for pid %d", config.Pid, config.Pid)
+	}
+
 	m := &MetricSet{
 		BaseMetricSet: base,
 		stats: &process.Stats{