diff --git a/opts/opts.go b/opts/opts.go
index f15064ac69..3d8c23ff77 100644
--- a/opts/opts.go
+++ b/opts/opts.go
@@ -3,7 +3,6 @@ package opts
 import (
 	"fmt"
 	"net"
-	"net/url"
 	"os"
 	"path"
 	"regexp"
@@ -39,10 +38,6 @@ func IPVar(value *net.IP, names []string, defaultValue, usage string) {
 	flag.Var(NewIpOpt(value, defaultValue), names, usage)
 }
 
-func MirrorListVar(values *[]string, names []string, usage string) {
-	flag.Var(newListOptsRef(values, ValidateMirror), names, usage)
-}
-
 func LabelListVar(values *[]string, names []string, usage string) {
 	flag.Var(newListOptsRef(values, ValidateLabel), names, usage)
 }
@@ -127,6 +122,7 @@ func (opts *ListOpts) Len() int {
 
 // Validators
 type ValidatorFctType func(val string) (string, error)
+type ValidatorFctListType func(val string) ([]string, error)
 
 func ValidateAttach(val string) (string, error) {
 	s := strings.ToLower(val)
@@ -214,24 +210,6 @@ func ValidateExtraHost(val string) (string, error) {
 	return val, nil
 }
 
-// Validates an HTTP(S) registry mirror
-func ValidateMirror(val string) (string, error) {
-	uri, err := url.Parse(val)
-	if err != nil {
-		return "", fmt.Errorf("%s is not a valid URI", val)
-	}
-
-	if uri.Scheme != "http" && uri.Scheme != "https" {
-		return "", fmt.Errorf("Unsupported scheme %s", uri.Scheme)
-	}
-
-	if uri.Path != "" || uri.RawQuery != "" || uri.Fragment != "" {
-		return "", fmt.Errorf("Unsupported path/query/fragment at end of the URI")
-	}
-
-	return fmt.Sprintf("%s://%s/v1/", uri.Scheme, uri.Host), nil
-}
-
 func ValidateLabel(val string) (string, error) {
 	if strings.Count(val, "=") != 1 {
 		return "", fmt.Errorf("bad attribute format: %s", val)
diff --git a/opts/opts_test.go b/opts/opts_test.go
index 09b5aa780b..e813c44326 100644
--- a/opts/opts_test.go
+++ b/opts/opts_test.go
@@ -30,7 +30,23 @@ func TestValidateIPAddress(t *testing.T) {
 func TestListOpts(t *testing.T) {
 	o := NewListOpts(nil)
 	o.Set("foo")
-	o.String()
+	if o.String() != "[foo]" {
+		t.Errorf("%s != [foo]", o.String())
+	}
+	o.Set("bar")
+	if o.Len() != 2 {
+		t.Errorf("%d != 2", o.Len())
+	}
+	if !o.Get("bar") {
+		t.Error("o.Get(\"bar\") == false")
+	}
+	if o.Get("baz") {
+		t.Error("o.Get(\"baz\") == true")
+	}
+	o.Delete("foo")
+	if o.String() != "[bar]" {
+		t.Errorf("%s != [bar]", o.String())
+	}
 }
 
 func TestValidateDnsSearch(t *testing.T) {