diff --git a/cmd/hyperkube/hyperkube.go b/cmd/hyperkube/hyperkube.go
index 1d5511787c6..de65b3fea74 100644
--- a/cmd/hyperkube/hyperkube.go
+++ b/cmd/hyperkube/hyperkube.go
@@ -70,7 +70,7 @@ func (hk *HyperKube) Flags() *pflag.FlagSet {
 	if hk.baseFlags == nil {
 		hk.baseFlags = pflag.NewFlagSet(hk.Name, pflag.ContinueOnError)
 		hk.baseFlags.SetOutput(ioutil.Discard)
-		hk.baseFlags.SetWordSeparators([]string{"-", "_"})
+		hk.baseFlags.SetNormalizeFunc(util.WordSepNormalizeFunc)
 		hk.baseFlags.BoolVarP(&hk.helpFlagVal, "help", "h", false, "help for "+hk.Name)
 
 		// These will add all of the "global" flags (defined with both the
diff --git a/cmd/hyperkube/server.go b/cmd/hyperkube/server.go
index 4bf5422f3ad..68ec7e663ef 100644
--- a/cmd/hyperkube/server.go
+++ b/cmd/hyperkube/server.go
@@ -68,7 +68,7 @@ func (s *Server) Flags() *pflag.FlagSet {
 	if s.flags == nil {
 		s.flags = pflag.NewFlagSet(s.Name(), pflag.ContinueOnError)
 		s.flags.SetOutput(ioutil.Discard)
-		s.flags.SetWordSeparators([]string{"-", "_"})
+		s.flags.SetNormalizeFunc(util.WordSepNormalizeFunc)
 	}
 	return s.flags
 }
diff --git a/cmd/kube-version-change/version.go b/cmd/kube-version-change/version.go
index 9e6936ea80b..b466c6b299b 100644
--- a/cmd/kube-version-change/version.go
+++ b/cmd/kube-version-change/version.go
@@ -31,6 +31,7 @@ import (
 	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1beta1"
 	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1beta2"
 	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/api/v1beta3"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 
 	"github.com/ghodss/yaml"
 	flag "github.com/spf13/pflag"
@@ -55,7 +56,7 @@ func isYAML(data []byte) bool {
 
 func main() {
 	runtime.GOMAXPROCS(runtime.NumCPU())
-	flag.CommandLine.SetWordSeparators([]string{"-", "_"})
+	flag.CommandLine.SetNormalizeFunc(util.WordSepNormalizeFunc)
 	flag.Parse()
 
 	if *rewrite != "" {
diff --git a/pkg/kubectl/cmd/util/factory.go b/pkg/kubectl/cmd/util/factory.go
index 312230b395c..eb7b4bbd448 100644
--- a/pkg/kubectl/cmd/util/factory.go
+++ b/pkg/kubectl/cmd/util/factory.go
@@ -86,7 +86,7 @@ func NewFactory(optionalClientConfig clientcmd.ClientConfig) *Factory {
 	mapper := kubectl.ShortcutExpander{latest.RESTMapper}
 
 	flags := pflag.NewFlagSet("", pflag.ContinueOnError)
-	flags.SetWordSeparators([]string{"-", "_"})
+	flags.SetNormalizeFunc(util.WordSepNormalizeFunc)
 
 	clientConfig := optionalClientConfig
 	if optionalClientConfig == nil {
diff --git a/pkg/util/flags.go b/pkg/util/flags.go
index 87c3f38e1ea..c22ea1d581c 100644
--- a/pkg/util/flags.go
+++ b/pkg/util/flags.go
@@ -16,11 +16,23 @@ limitations under the License.
 
 package util
 
+import "strings"
+
 import "github.com/spf13/pflag"
 
+func WordSepNormalizeFunc(f *pflag.FlagSet, name string) pflag.NormalizedName {
+	from := []string{"-", "_"}
+	to := "."
+	for _, sep := range from {
+		name = strings.Replace(name, sep, to, -1)
+	}
+	// Type convert to indicate normalization has been done.
+	return pflag.NormalizedName(name)
+}
+
 // InitFlags normalizes and parses the command line flags
 func InitFlags() {
-	pflag.CommandLine.SetWordSeparators([]string{"-", "_"})
+	pflag.CommandLine.SetNormalizeFunc(WordSepNormalizeFunc)
 	AddAllFlagsToPFlags()
 	pflag.Parse()
 }