diff --git a/docker.go b/docker.go
index 77a1f6f73..45a29b8c6 100644
--- a/docker.go
+++ b/docker.go
@@ -8,6 +8,7 @@ import (
 	"text/template"
 	"time"
 
+	"fmt"
 	"github.com/BurntSushi/toml"
 	"github.com/BurntSushi/ty/fun"
 	log "github.com/Sirupsen/logrus"
@@ -137,10 +138,8 @@ func (provider *DockerProvider) loadDockerConfig(dockerClient *docker.Client) *C
 			log.Debugf("Filtering disabled container %s", container.Name)
 			return false
 		}
-		_, errRule := provider.getLabel(container, "traefik.frontend.rule")
-		_, errValue := provider.getLabel(container, "traefik.frontend.value")
 
-		if errRule != nil && errValue == nil || errRule == nil && errValue != nil {
+		if _, err := provider.getLabels(container, []string{"traefik.frontend.rule", "traefik.frontend.value"}); err != nil {
 			log.Debugf("Filtering bad labeled container %s", container.Name)
 			return false
 		}
@@ -196,7 +195,8 @@ func (provider *DockerProvider) loadDockerConfig(dockerClient *docker.Client) *C
 
 func (provider *DockerProvider) getFrontendName(container docker.Container) string {
 	// Replace '.' with '-' in quoted keys because of this issue https://github.com/BurntSushi/toml/issues/78
-	return strings.Replace(provider.GetFrontendRule(container)+"-"+provider.GetFrontendValue(container), ".", "-", -1)
+	frontendName := fmt.Sprintf("%s-%s", provider.GetFrontendRule(container), provider.GetFrontendValue(container))
+	return strings.Replace(frontendName, ".", "-", -1)
 }
 
 func (provider *DockerProvider) getEscapedName(name string) string {
@@ -212,6 +212,18 @@ func (provider *DockerProvider) getLabel(container docker.Container, label strin
 	return "", errors.New("Label not found:" + label)
 }
 
+func (provider *DockerProvider) getLabels(container docker.Container, labels []string) (map[string]string, error) {
+	foundLabels := map[string]string{}
+	for _, label := range labels {
+		if foundLabel, err := provider.getLabel(container, label); err != nil {
+			return nil, errors.New("Label not found: " + label)
+		} else {
+			foundLabels[label] = foundLabel
+		}
+	}
+	return foundLabels, nil
+}
+
 func (provider *DockerProvider) GetFrontendValue(container docker.Container) string {
 	if label, err := provider.getLabel(container, "traefik.frontend.value"); err == nil {
 		return label
diff --git a/marathon.go b/marathon.go
index 4d9271e69..f79558d0a 100644
--- a/marathon.go
+++ b/marathon.go
@@ -64,12 +64,12 @@ func (provider *MarathonProvider) loadMarathonConfig() *Configuration {
 			return ""
 		},
 		"getWeight": func(task marathon.Task, applications []marathon.Application) string {
-			application := getApplication(task, applications)
-			if application == nil {
+			application, errApp := getApplication(task, applications)
+			if errApp != nil {
 				log.Errorf("Unable to get marathon application from task %s", task.AppID)
 				return "0"
 			}
-			if label, err := provider.getLabel(*application, "traefik.weight"); err == nil {
+			if label, err := provider.getLabel(application, "traefik.weight"); err == nil {
 				return label
 			}
 			return "0"
@@ -84,12 +84,12 @@ func (provider *MarathonProvider) loadMarathonConfig() *Configuration {
 			return strings.Replace(s3, s1, s2, -1)
 		},
 		"getProtocol": func(task marathon.Task, applications []marathon.Application) string {
-			application := getApplication(task, applications)
-			if application == nil {
+			application, errApp := getApplication(task, applications)
+			if errApp != nil {
 				log.Errorf("Unable to get marathon application from task %s", task.AppID)
 				return "http"
 			}
-			if label, err := provider.getLabel(*application, "traefik.protocol"); err == nil {
+			if label, err := provider.getLabel(application, "traefik.protocol"); err == nil {
 				return label
 			}
 			return "http"
@@ -117,8 +117,8 @@ func (provider *MarathonProvider) loadMarathonConfig() *Configuration {
 			log.Debug("Filtering marathon task without port", task.AppID)
 			return false
 		}
-		application := getApplication(task, applications.Apps)
-		if application == nil {
+		application, errApp := getApplication(task, applications.Apps)
+		if errApp != nil {
 			log.Errorf("Unable to get marathon application from task %s", task.AppID)
 			return false
 		}
@@ -193,13 +193,13 @@ func (provider *MarathonProvider) loadMarathonConfig() *Configuration {
 	return configuration
 }
 
-func getApplication(task marathon.Task, apps []marathon.Application) *marathon.Application {
+func getApplication(task marathon.Task, apps []marathon.Application) (marathon.Application, error) {
 	for _, application := range apps {
 		if application.ID == task.AppID {
-			return &application
+			return application, nil
 		}
 	}
-	return nil
+	return marathon.Application{}, errors.New("Application not found: " + task.AppID)
 }
 
 func (provider *MarathonProvider) getLabel(application marathon.Application, label string) (string, error) {
diff --git a/middlewares/websocketproxy.go b/middlewares/websocketproxy.go
index b377b9940..7d497016d 100644
--- a/middlewares/websocketproxy.go
+++ b/middlewares/websocketproxy.go
@@ -133,7 +133,7 @@ func (w *WebsocketProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	connBackend, resp, err := dialer.Dial(backendURL.String(), nil)
 	if err != nil {
 		log.Errorf("Websocketproxy: couldn't dial to remote backend url %s, %s, %+v", backendURL.String(), err, resp)
-		http.NotFound(rw, req)
+		http.Error(rw, "Remote backend unreachable", http.StatusBadGateway)
 		return
 	}
 	defer connBackend.Close()