diff --git a/examples/advanced/README.md b/examples/advanced/README.md
index 3309be9..3fe7b7d 100644
--- a/examples/advanced/README.md
+++ b/examples/advanced/README.md
@@ -21,11 +21,11 @@ resource "virtomize_iso" "debian_iso" {
     networks = [{
       dhcp = true
       no_internet = false,
-      mac = "00-1B-63-84-45-E5"
+      mac = "ca:8c:65:0d:e7:57"
 },{
       dhcp = false
       domain = "custom_domain"
-      mac = "00-1B-63-84-45-E6"
+      mac = "ca:8c:65:0d:e7:58"
       ip_net = "10.0.0.0/24"
       gateway = "10.0.0.1"
       dns = ["1.1.1.1", "8.8.8.8"]
@@ -82,7 +82,7 @@ Please consult your network admin for the correct values for these parameters.
 {
       dhcp = false
       domain = "custom_domain"
-      mac = "00-1B-63-84-45-E6"
+      mac = "ca:8c:65:0d:e7:58"
       ip_net = "10.0.0.0/24"
       gateway = "10.0.0.1"
       dns = ["1.1.1.1", "8.8.8.8"]
diff --git a/examples/advanced/virtomize.tf b/examples/advanced/virtomize.tf
index 16bd717..7c7a7fc 100644
--- a/examples/advanced/virtomize.tf
+++ b/examples/advanced/virtomize.tf
@@ -34,11 +34,11 @@ resource "virtomize_iso" "debian_iso" {
     networks = [{
       dhcp = true
       no_internet = false
-      mac = "00-1B-63-84-45-E5"
+      mac = "ca:8c:65:0d:e7:57"
 },{
       dhcp = false
       domain = "custom_domain"
-      mac = "00-1B-63-84-45-E6"
+      mac = "ca:8c:65:0d:e7:58"
       ip_net = "10.0.0.0/24"
       gateway = "10.0.0.1"
       dns = ["1.1.1.1", "8.8.8.8"]
diff --git a/examples/vmware/README.md b/examples/vmware/README.md
index 2627f94..36ec1da 100644
--- a/examples/vmware/README.md
+++ b/examples/vmware/README.md
@@ -99,10 +99,15 @@ To use multiple network adapters, follow
 [the official documentation](https://registry.terraform.io/providers/hashicorp/vsphere/1.17.0/docs/resources/virtual_machine) 
 and add the `use_static_mac` and  `mac_address` properties to the individual network interfaces.
 
+Notice that at least in our test the vSphere provider prefer MAC addresses to be in the format
+`xx:xx:xx:xx:xx:xx`
+instead of
+`xx-xx-xx-xx-xx-xx`.
+
 ```terraform
   network_interface {
     network_id     = "${data.vsphere_network.mgmt_lan.id}"
     use_static_mac = true
-    mac_address    = "CA-8C-65-0D-E7-58"
+    mac_address    = "ca:8c:65:0d:e7:57"
 }
 ```
\ No newline at end of file
diff --git a/provider/provider_test.go b/provider/provider_test.go
index 196b330..4f0f02b 100644
--- a/provider/provider_test.go
+++ b/provider/provider_test.go
@@ -47,6 +47,43 @@ resource "virtomize_iso" "debian_iso" {
 	})
 }
 
+func TestSimpleIsoLifeCycleStaticConfig(t *testing.T) {
+	testConfiguration := `
+provider "virtomize" {
+  # apitoken = retrieved from env variables
+  # localstorage = use local folder
+}
+
+resource "virtomize_iso" "debian_iso" {
+    name = "debian_iso"
+    distribution = "debian"
+    version = "11"
+    hostname = "examplehost"
+    networks = [{
+      dhcp = false
+      domain = "custom_domain"
+      mac = "ca:8c:65:0d:e7:58"
+      ip_net = "10.0.0.0/24"
+      gateway = "10.0.0.1"
+      dns = ["1.1.1.1", "8.8.8.8"]
+      no_internet = false
+    }]
+ }`
+
+	resource.Test(t, resource.TestCase{
+		PreCheck:                 func() { testAccPreCheck(t) },
+		ProtoV6ProviderFactories: testAccProtoV6ProviderFactories,
+		Steps: []resource.TestStep{
+			{
+				Config: testConfiguration,
+				Check: resource.ComposeTestCheckFunc(
+					checkSimpleIsoProperties,
+				),
+			},
+		},
+	})
+}
+
 func checkSimpleIsoProperties(state *terraform.State) error {
 	resource_name := "virtomize_iso.debian_iso"
 	rs, ok := state.RootModule().Resources[resource_name]
diff --git a/provider/resource_iso.go b/provider/resource_iso.go
index 6df71af..3d57536 100644
--- a/provider/resource_iso.go
+++ b/provider/resource_iso.go
@@ -324,7 +324,7 @@ func stringListWithValidElements(list []types.String) []string {
 			continue
 		}
 
-		result = append(result, item.String())
+		result = append(result, item.ValueString())
 	}
 
 	return result