diff --git a/pkg/cloudprovider/controller/nodecontroller.go b/pkg/cloudprovider/controller/nodecontroller.go
index 58ddc7e2e22..7a596589f51 100644
--- a/pkg/cloudprovider/controller/nodecontroller.go
+++ b/pkg/cloudprovider/controller/nodecontroller.go
@@ -40,6 +40,11 @@ var (
 	ErrCloudInstance  = errors.New("cloud provider doesn't support instances.")
 )
 
+var (
+	// aliased to allow mocking in tests
+	lookupIP = net.LookupIP
+)
+
 type NodeController struct {
 	cloud              cloudprovider.Interface
 	matchRE            string
@@ -285,7 +290,7 @@ func (s *NodeController) PopulateIPs(nodes *api.NodeList) (*api.NodeList, error)
 			if addr != nil {
 				node.Status.HostIP = node.Name
 			} else {
-				addrs, err := net.LookupIP(node.Name)
+				addrs, err := lookupIP(node.Name)
 				if err != nil {
 					glog.Errorf("Can't get ip address of node %s: %v", node.Name, err)
 				} else if len(addrs) == 0 {
diff --git a/pkg/cloudprovider/controller/nodecontroller_test.go b/pkg/cloudprovider/controller/nodecontroller_test.go
index dfaa0250071..c1eb6bfb059 100644
--- a/pkg/cloudprovider/controller/nodecontroller_test.go
+++ b/pkg/cloudprovider/controller/nodecontroller_test.go
@@ -18,6 +18,7 @@ package controller
 
 import (
 	"errors"
+	"fmt"
 	"net"
 	"reflect"
 	"sort"
@@ -51,6 +52,12 @@ type FakeNodeHandler struct {
 	RequestCount int
 }
 
+func init() {
+	lookupIP = func(host string) ([]net.IP, error) {
+		return nil, fmt.Errorf("lookup %v: no such host", host)
+	}
+}
+
 func (c *FakeNodeHandler) Nodes() client.NodeInterface {
 	return c
 }