@@ -92,10 +92,10 @@ func NewCmdEnv(fullName string, f *clientcmd.Factory, in io.Reader, out io.Write

 	return cmd

 }

-func validateNoOverwrites(meta *kapi.ObjectMeta, labels map[string]string) error {

-	for key := range labels {

-		if value, found := meta.Labels[key]; found {

-			return fmt.Errorf("'%s' already has a value (%s), and --overwrite is false", key, value)

+func validateNoOverwrites(existing []kapi.EnvVar, env []kapi.EnvVar) error {

+	for _, e := range env {

+		if current, exists := findEnv(existing, e.Name); exists && current.Value != e.Value {

+			return fmt.Errorf("'%s' already has a value (%s), and --overwrite is false", current.Name, current.Value)

 		}

 	}

 	return nil

@@ -116,7 +116,7 @@ func RunEnv(f *clientcmd.Factory, in io.Reader, out io.Writer, cmd *cobra.Comman

 	list := kcmdutil.GetFlagBool(cmd, "list")

 	selector := kcmdutil.GetFlagString(cmd, "selector")

 	all := kcmdutil.GetFlagBool(cmd, "all")

-	//overwrite := kcmdutil.GetFlagBool(cmd, "overwrite")

+	overwrite := kcmdutil.GetFlagBool(cmd, "overwrite")

 	resourceVersion := kcmdutil.GetFlagString(cmd, "resource-version")

 	outputFormat := kcmdutil.GetFlagString(cmd, "output")

@@ -177,6 +177,7 @@ func RunEnv(f *clientcmd.Factory, in io.Reader, out io.Writer, cmd *cobra.Comman

 	}

 	skipped := 0

+	errored := 0

 	for _, info := range infos {

 		ok, err := f.UpdatePodSpecForObject(info.Object, func(spec *kapi.PodSpec) error {

 			containers, _ := selectContainers(spec.Containers, containerMatch)

@@ -185,6 +186,13 @@ func RunEnv(f *clientcmd.Factory, in io.Reader, out io.Writer, cmd *cobra.Comman

 				return nil

 			}

 			for _, c := range containers {

+				if !overwrite {

+					if err := validateNoOverwrites(c.Env, env); err != nil {

+						errored++

+						return err

+					}

+				}

+

 				c.Env = updateEnv(c.Env, env, remove)

 				if list {

@@ -207,6 +215,12 @@ func RunEnv(f *clientcmd.Factory, in io.Reader, out io.Writer, cmd *cobra.Comman

 				if vars == nil {

 					return fmt.Errorf("no environment variables provided")

 				}

+				if !overwrite {

+					if err := validateNoOverwrites(*vars, env); err != nil {

+						errored++

+						return err

+					}

+				}

 				*vars = updateEnv(*vars, env, remove)

 				if list {

 					fmt.Fprintf(out, "# %s %s\n", info.Mapping.Resource, info.Name)

@@ -229,6 +243,9 @@ func RunEnv(f *clientcmd.Factory, in io.Reader, out io.Writer, cmd *cobra.Comman

 	if one && skipped == len(infos) {

 		return fmt.Errorf("%s/%s is not a pod or does not have a pod template", infos[0].Mapping.Resource, infos[0].Name)

 	}

+	if errored == len(infos) {

+		return fmt.Errorf("no environment variable has been set")

+	}

 	if list {

 		return nil

@@ -214,7 +214,10 @@ os::test::junit::declare_suite_end

 os::test::junit::declare_suite_start "cmd/basicresources/setenv"

 os::cmd::expect_success "oc create -f test/integration/testdata/test-deployment-config.yaml"

 os::cmd::expect_success "oc create -f test/integration/testdata/test-buildcli.json"

-os::cmd::expect_success_and_text "oc set env dc/test-deployment-config FOO=bar" "updated"

+os::cmd::expect_success_and_text "oc set env dc/test-deployment-config FOO=1st" "updated"

+os::cmd::expect_success_and_text "oc set env dc/test-deployment-config FOO=2nd" "updated"

+os::cmd::expect_success_and_text "oc set env dc/test-deployment-config FOO=bar --overwrite" "updated"

+os::cmd::expect_failure_and_text "oc set env dc/test-deployment-config FOO=zee --overwrite=false" "already has a value"

 os::cmd::expect_success_and_text "oc set env dc/test-deployment-config --list" "FOO=bar"

 os::cmd::expect_success_and_text "oc set env bc --all FOO=bar" "updated"

 os::cmd::expect_success_and_text "oc set env bc --all --list" "FOO=bar"