@@ -10,6 +10,8 @@ import (

 	"github.com/pkg/errors"

 )

+const defaultSocketGroup = "docker"

+

 func lookupGID(name string) (int, error) {

 	groupFile, err := user.GetGroupPath()

 	if err != nil {

@@ -4,7 +4,9 @@ import (

 	"crypto/tls"

 	"fmt"

 	"net"

+	"os"

+	"github.com/Sirupsen/logrus"

 	"github.com/docker/go-connections/sockets"

 )

@@ -20,7 +22,11 @@ func Init(proto, addr, socketGroup string, tlsConfig *tls.Config) (ls []net.List

 	case "unix":

 		gid, err := lookupGID(socketGroup)

 		if err != nil {

-			return nil, err

+			if socketGroup != defaultSocketGroup {

+				return nil, err

+			}

+			logrus.Warnf("could not change group %s to %s: %v", addr, defaultSocketGroup, err)

+			gid = os.Getgid()

 		}

 		l, err := sockets.NewUnixSocket(addr, gid)

 		if err != nil {

@@ -6,8 +6,10 @@ import (

 	"crypto/tls"

 	"fmt"

 	"net"

+	"os"

 	"strconv"

+	"github.com/Sirupsen/logrus"

 	"github.com/coreos/go-systemd/activation"

 	"github.com/docker/go-connections/sockets"

 )

@@ -33,7 +35,11 @@ func Init(proto, addr, socketGroup string, tlsConfig *tls.Config) ([]net.Listene

 	case "unix":

 		gid, err := lookupGID(socketGroup)

 		if err != nil {

-			return nil, err

+			if socketGroup != defaultSocketGroup {

+				return nil, err

+			}

+			logrus.Warnf("could not change group %s to %s: %v", addr, defaultSocketGroup, err)

+			gid = os.Getgid()

 		}

 		l, err := sockets.NewUnixSocket(addr, gid)

 		if err != nil {