diff --git a/pkg/kubelet/server/stats/summary.go b/pkg/kubelet/server/stats/summary.go
index 8b889884224..4b8f326dca5 100644
--- a/pkg/kubelet/server/stats/summary.go
+++ b/pkg/kubelet/server/stats/summary.go
@@ -344,7 +344,7 @@ func (sb *summaryBuilder) containerInfoV2ToNetworkStats(name string, info *cadvi
 			}
 		}
 	}
-	glog.Warningf("Missing default interface %q for s", network.DefaultInterfaceName, name)
+	glog.Warningf("Missing default interface %q for %s", network.DefaultInterfaceName, name)
 	return nil
 }
 
diff --git a/pkg/kubelet/server/stats/summary_test.go b/pkg/kubelet/server/stats/summary_test.go
index a90031c0806..e78cbe27812 100644
--- a/pkg/kubelet/server/stats/summary_test.go
+++ b/pkg/kubelet/server/stats/summary_test.go
@@ -321,6 +321,7 @@ func testTime(base time.Time, seed int) time.Time {
 }
 
 func checkNetworkStats(t *testing.T, label string, seed int, stats *kubestats.NetworkStats) {
+	assert.NotNil(t, stats)
 	assert.EqualValues(t, testTime(timestamp, seed).Unix(), stats.Time.Time.Unix(), label+".Net.Time")
 	assert.EqualValues(t, seed+offsetNetRxBytes, *stats.RxBytes, label+".Net.RxBytes")
 	assert.EqualValues(t, seed+offsetNetRxErrors, *stats.RxErrors, label+".Net.RxErrors")