diff --git a/linux/shim/client.go b/linux/shim/client.go
index 2b5016fc5..f34403ceb 100644
--- a/linux/shim/client.go
+++ b/linux/shim/client.go
@@ -49,6 +49,7 @@ func WithStart(binary, address string, debug bool) ClientOpt {
 			if err != nil {
 				terminate(cmd)
 			}
+			reaper.Default.Delete(cmd.Process.Pid)
 		}()
 		log.G(ctx).WithFields(logrus.Fields{
 			"pid":     cmd.Process.Pid,
diff --git a/metrics/cgroups/cgroups.go b/metrics/cgroups/cgroups.go
index 5ef16c0c3..31d2f2148 100644
--- a/metrics/cgroups/cgroups.go
+++ b/metrics/cgroups/cgroups.go
@@ -65,6 +65,7 @@ func (m *cgroupsMonitor) Monitor(c runtime.Task) error {
 func (m *cgroupsMonitor) Stop(c runtime.Task) error {
 	info := c.Info()
 	m.collector.Remove(info.ID, info.Namespace)
+	m.oom.Remove(info.ID, info.Namespace)
 	return nil
 }
 
diff --git a/metrics/cgroups/oom.go b/metrics/cgroups/oom.go
index 47d979f58..fd1845c1f 100644
--- a/metrics/cgroups/oom.go
+++ b/metrics/cgroups/oom.go
@@ -9,6 +9,7 @@ import (
 
 	"github.com/containerd/cgroups"
 	metrics "github.com/docker/go-metrics"
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/sirupsen/logrus"
 )
 
@@ -18,20 +19,21 @@ func NewOOMCollector(ns *metrics.Namespace) (*OOMCollector, error) {
 		return nil, err
 	}
 	c := &OOMCollector{
-		fd:        fd,
-		memoryOOM: ns.NewLabeledGauge("memory_oom", "The number of times a container received an oom event", metrics.Total, "container_id", "namespace"),
-		set:       make(map[uintptr]*oom),
+		fd:   fd,
+		set:  make(map[uintptr]*oom),
+		desc: ns.NewDesc("memory_oom", "The number of times a container has received an oom event", metrics.Total, "container_id", "namespace"),
 	}
 	go c.start()
+	ns.Add(c)
 	return c, nil
 }
 
 type OOMCollector struct {
 	mu sync.Mutex
 
-	memoryOOM metrics.LabeledGauge
-	fd        int
-	set       map[uintptr]*oom
+	fd   int
+	set  map[uintptr]*oom
+	desc *prometheus.Desc
 }
 
 type oom struct {
@@ -39,6 +41,7 @@ type oom struct {
 	namespace string
 	c         cgroups.Cgroup
 	triggers  []Trigger
+	count     int
 }
 
 func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...Trigger) error {
@@ -50,12 +53,10 @@ func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...
 	}
 	o.set[fd] = &oom{
 		id:        id,
+		namespace: namespace,
 		c:         cg,
 		triggers:  triggers,
-		namespace: namespace,
 	}
-	// set the gauge's default value
-	o.memoryOOM.WithValues(id, namespace).Set(0)
 	event := unix.EpollEvent{
 		Fd:     int32(fd),
 		Events: unix.EPOLLHUP | unix.EPOLLIN | unix.EPOLLERR,
@@ -66,11 +67,37 @@ func (o *OOMCollector) Add(id, namespace string, cg cgroups.Cgroup, triggers ...
 	return nil
 }
 
+func (o *OOMCollector) Remove(id, namespace string) {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+	for fd, t := range o.set {
+		if t.id == id && t.namespace == namespace {
+			unix.Close(int(fd))
+			delete(o.set, fd)
+			return
+		}
+	}
+}
+
 // Close closes the epoll fd
 func (o *OOMCollector) Close() error {
 	return unix.Close(int(o.fd))
 }
 
+func (o *OOMCollector) Describe(ch chan<- *prometheus.Desc) {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+	ch <- o.desc
+}
+
+func (o *OOMCollector) Collect(ch chan<- prometheus.Metric) {
+	o.mu.Lock()
+	defer o.mu.Unlock()
+	for _, t := range o.set {
+		ch <- prometheus.MustNewConstMetric(o.desc, prometheus.GaugeValue, float64(t.count), t.id, t.namespace)
+	}
+}
+
 func (o *OOMCollector) start() {
 	var events [128]unix.EpollEvent
 	for {
@@ -107,7 +134,7 @@ func (o *OOMCollector) process(fd uintptr, event uint32) {
 		unix.Close(int(fd))
 		return
 	}
-	o.memoryOOM.WithValues(info.id, info.namespace).Inc(1)
+	info.count++
 	for _, t := range info.triggers {
 		t(info.id, info.c)
 	}
diff --git a/runtime/task.go b/runtime/task.go
index 4a5685e10..62fa171e6 100644
--- a/runtime/task.go
+++ b/runtime/task.go
@@ -9,7 +9,6 @@ import (
 type TaskInfo struct {
 	ID        string
 	Runtime   string
-	Spec      []byte
 	Namespace string
 }