diff --git a/docs/resources/dedicated_server_installation.md b/docs/resources/dedicated_server_installation.md
index 136e1cc3..74fa54f8 100644
--- a/docs/resources/dedicated_server_installation.md
+++ b/docs/resources/dedicated_server_installation.md
@@ -40,7 +40,7 @@ resource "leaseweb_dedicated_server_installation" "example" {
 - `hostname` (String) Hostname to be used in your installation
 - `partitions` (Attributes List) (see [below for nested schema](#nestedatt--partitions))
 - `password` (String) Server root password. If not provided, it would be automatically generated
-- `post_install_script` (String) Base64 Encoded string containing a valid bash script to be run right after the installation
+- `post_install_script` (String) A valid bash script to run right after the installation.
 - `power_cycle` (Boolean) If true, allows system reboots to happen automatically within the process. Otherwise, you should do them manually
 - `raid` (Attributes) (see [below for nested schema](#nestedatt--raid))
 - `ssh_keys` (Set of String) List of public sshKeys to be setup in your installation
diff --git a/examples/resources/leaseweb_dedicated_server_installation/resource.tf b/examples/resources/leaseweb_dedicated_server_installation/resource.tf
index 42dbf3ee..867d537d 100644
--- a/examples/resources/leaseweb_dedicated_server_installation/resource.tf
+++ b/examples/resources/leaseweb_dedicated_server_installation/resource.tf
@@ -3,3 +3,13 @@ resource "leaseweb_dedicated_server_installation" "example" {
   dedicated_server_id = "12345"
   operating_system_id = "UBUNTU_22_04_64BIT"
 }
+
+# Example install operating system on dedicated server with post_install_script
+resource "leaseweb_dedicated_server_installation" "example" {
+  dedicated_server_id = "12345"
+  operating_system_id = "UBUNTU_22_04_64BIT"
+  post_install_script = <<-EOS
+      #!/bin/sh
+      apt install nginx -y -qq
+  EOS
+}
\ No newline at end of file
diff --git a/internal/provider/dedicatedserver/installation_resource.go b/internal/provider/dedicatedserver/installation_resource.go
index 0edd97e7..bc105cd7 100644
--- a/internal/provider/dedicatedserver/installation_resource.go
+++ b/internal/provider/dedicatedserver/installation_resource.go
@@ -2,6 +2,7 @@ package dedicatedserver
 
 import (
 	"context"
+	"encoding/base64"
 	"strings"
 
 	"github.com/hashicorp/terraform-plugin-framework-validators/int32validator"
@@ -203,7 +204,7 @@ func (i *installationResource) Schema(
 				},
 			},
 			"post_install_script": schema.StringAttribute{
-				Description: "Base64 Encoded string containing a valid bash script to be run right after the installation",
+				Description: "A valid bash script to run right after the installation.",
 				Optional:    true,
 				PlanModifiers: []planmodifier.String{
 					stringplanmodifier.RequiresReplace(),
@@ -315,7 +316,7 @@ func (i *installationResource) Create(
 	opts.Hostname = utils.AdaptStringPointerValueToNullableString(plan.Hostname)
 	opts.Partitions = partitions
 	opts.Password = utils.AdaptStringPointerValueToNullableString(plan.Password)
-	opts.PostInstallScript = utils.AdaptStringPointerValueToNullableString(plan.PostInstallScript)
+	opts.PostInstallScript = utils.AdaptStringValueToNullableString(base64.StdEncoding.EncodeToString([]byte(strings.TrimSpace(plan.PostInstallScript.ValueString()))))
 	opts.PowerCycle = utils.AdaptBoolPointerValueToNullableBool(plan.PowerCycle)
 	opts.Raid = raid
 	opts.Timezone = utils.AdaptStringPointerValueToNullableString(plan.Timezone)
diff --git a/internal/provider/provider_test.go b/internal/provider/provider_test.go
index 7f687c31..88fc2bf2 100644
--- a/internal/provider/provider_test.go
+++ b/internal/provider/provider_test.go
@@ -1418,7 +1418,10 @@ func TestAccDedicatedServerInstallationResource(t *testing.T) {
 							device = "SATA2TB"
 							hostname = "example.com"
 							password = "password"
-							post_install_script = "c2NyaXB0LnNo"
+							post_install_script = <<-EOS
+								#!/bin/sh
+								apt install nginx -y -qq
+							EOS
 							power_cycle = true
 							ssh_keys = ["tralala"]
 							timezone = "UTC"
@@ -1455,6 +1458,11 @@ func TestAccDedicatedServerInstallationResource(t *testing.T) {
 								"id",
 								"bcf2bedf-8450-4b22-86a8-f30aeb3a38f9",
 							),
+							resource.TestCheckResourceAttr(
+								"leaseweb_dedicated_server_installation.test",
+								"post_install_script",
+								"#!/bin/sh\napt install nginx -y -qq\n",
+							),
 						),
 					},
 				},
diff --git a/internal/utils/value_adapters.go b/internal/utils/value_adapters.go
index 6dfb3a7b..43c75a4c 100644
--- a/internal/utils/value_adapters.go
+++ b/internal/utils/value_adapters.go
@@ -124,6 +124,14 @@ func AdaptStringPointerValueToNullableString(value types.String) *string {
 	return value.ValueStringPointer()
 }
 
+func AdaptStringValueToNullableString(value string) *string {
+	if value == "" {
+		return nil
+	}
+
+	return &value
+}
+
 func AdaptStringTypeArrayToStringArray[T ~string](types []T) []string {
 	var convertedTypes []string
 
diff --git a/internal/utils/value_adapters_test.go b/internal/utils/value_adapters_test.go
index 3868bec5..1318de9a 100644
--- a/internal/utils/value_adapters_test.go
+++ b/internal/utils/value_adapters_test.go
@@ -425,3 +425,15 @@ func ExampleAdaptNullableSdkModelToResourceObject_second() {
 	fmt.Println(resourceModel)
 	// Output: <null>
 }
+
+func TestAdaptStringToNullableString(t *testing.T) {
+	t.Run("returns nil when value is empty", func(t *testing.T) {
+		assert.Nil(t, AdaptStringValueToNullableString(""))
+	})
+
+	t.Run("returns pointer when value is set", func(t *testing.T) {
+		value := "tralala"
+
+		assert.Equal(t, &value, AdaptStringValueToNullableString(value))
+	})
+}