diff --git a/generator/containers_test.go b/generator/containers_test.go
index a5e6b6d..97ac444 100644
--- a/generator/containers_test.go
+++ b/generator/containers_test.go
@@ -13,7 +13,7 @@ func TestContainers_TemplateData(t *testing.T) {
 	dockerClient.ContainersData = []types.Container{
 		{
 			Names: []string{
-				"container-name",
+				"/container-name",
 			},
 			NetworkSettings: &types.SummaryNetworkSettings{
 				Networks: map[string]*network.EndpointSettings{
@@ -24,7 +24,7 @@ func TestContainers_TemplateData(t *testing.T) {
 				},
 			},
 			Labels: map[string]string{
-				fmtLabel("%s"):               "{{index .Names 0}}.testdomain.com",
+				fmtLabel("%s"):               "{{trimPrefix \"/\" (index .Names 0)}}.testdomain.com",
 				fmtLabel("%s.reverse_proxy"): "{{(index .NetworkSettings.Networks \"caddy-network\").IPAddress}}:5000/api",
 			},
 		},
diff --git a/generator/labels.go b/generator/labels.go
index 3dff315..ccb7642 100644
--- a/generator/labels.go
+++ b/generator/labels.go
@@ -1,45 +1,38 @@
 package generator
 
 import (
+	"sort"
 	"strconv"
 	"strings"
-	"text/template"
-	"sort"
 
+	"github.com/Masterminds/sprig/v3"
 	"github.com/lucaslorentz/caddy-docker-proxy/v2/caddyfile"
 )
 
 type targetsProvider func() ([]string, error)
 
 func labelsToCaddyfile(labels map[string]string, templateData interface{}, getTargets targetsProvider) (*caddyfile.Container, error) {
-	funcMap := template.FuncMap{
-		"upstreams": func(options ...interface{}) (string, error) {
-			targets, err := getTargets()
-			sort.Strings(targets)
-			transformed := []string{}
-			for _, target := range targets {
-				for _, param := range options {
-					if protocol, isProtocol := param.(string); isProtocol {
-						target = protocol + "://" + target
-					} else if port, isPort := param.(int); isPort {
-						target = target + ":" + strconv.Itoa(port)
-					}
+	funcMap := sprig.TxtFuncMap()
+	funcMap["upstreams"] = func(options ...interface{}) (string, error) {
+		targets, err := getTargets()
+		sort.Strings(targets)
+		transformed := []string{}
+		for _, target := range targets {
+			for _, param := range options {
+				if protocol, isProtocol := param.(string); isProtocol {
+					target = protocol + "://" + target
+				} else if port, isPort := param.(int); isPort {
+					target = target + ":" + strconv.Itoa(port)
 				}
-				transformed = append(transformed, target)
 			}
-			sort.Strings(transformed)
-			return strings.Join(transformed, " "), err
-		},
-		"http": func() string {
-			return "http"
-		},
-		"https": func() string {
-			return "https"
-		},
-		"h2c": func() string {
-			return "h2c"
-		},
+			transformed = append(transformed, target)
+		}
+		sort.Strings(transformed)
+		return strings.Join(transformed, " "), err
 	}
+	funcMap["http"] = func() string { return "http" }
+	funcMap["https"] = func() string { return "https" }
+	funcMap["h2c"] = func() string { return "h2c" }
 
 	return caddyfile.FromLabels(labels, templateData, funcMap)
 }