diff --git a/ShippingRates/Helpers/DHLServicesValidator.cs b/ShippingRates/Helpers/DHLServicesValidator.cs
index 8a6d0f0..447750f 100644
--- a/ShippingRates/Helpers/DHLServicesValidator.cs
+++ b/ShippingRates/Helpers/DHLServicesValidator.cs
@@ -1,12 +1,10 @@
-using System;
-using System.Collections.Generic;
+using ShippingRates.ShippingProviders;
+using System;
 using System.Linq;
-using System.Text;
-using ShippingRates.ShippingProviders;
 
 namespace ShippingRates.Helpers
 {
-    public static class DHLServicesValidator
+    internal static class DHLServicesValidator
     {
         public static bool IsServiceValid(char c) =>
             DHLProvider.AvailableServices.ContainsKey(char.ToUpperInvariant(c));
diff --git a/ShippingRates/Helpers/Extensions/AddressExtensions.cs b/ShippingRates/Helpers/Extensions/AddressExtensions.cs
index e6cfe89..47708fa 100644
--- a/ShippingRates/Helpers/Extensions/AddressExtensions.cs
+++ b/ShippingRates/Helpers/Extensions/AddressExtensions.cs
@@ -1,13 +1,10 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-
-using ShippingRates.RateServiceWebReference;
 
 namespace ShippingRates.Helpers.Extensions
 {
-    public static class AddressExtensions
+    internal static class AddressExtensions
     {
         /// <summary>
         /// Get FedEx API address from ShippingRates.Address
diff --git a/ShippingRates/Helpers/Extensions/RequestedShipmentExtensions.cs b/ShippingRates/Helpers/Extensions/RequestedShipmentExtensions.cs
index c121052..1ed2764 100644
--- a/ShippingRates/Helpers/Extensions/RequestedShipmentExtensions.cs
+++ b/ShippingRates/Helpers/Extensions/RequestedShipmentExtensions.cs
@@ -1,16 +1,11 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-
-using ShippingRates.RateServiceWebReference;
+using ShippingRates.RateServiceWebReference;
 
 namespace ShippingRates.Helpers.Extensions
 {
     /// <summary>
     /// Extension methods for RequestedShipment
     /// </summary>
-    public static class RequestedShipmentExtensions
+    internal static class RequestedShipmentExtensions
     {
         /// <summary>
         /// Calculates the total weight for all packages in the requested shipment
diff --git a/ShippingRates/Helpers/Extensions/ShipmentOptionsExtensions.cs b/ShippingRates/Helpers/Extensions/ShipmentOptionsExtensions.cs
index 2f0e8a4..b07c53f 100644
--- a/ShippingRates/Helpers/Extensions/ShipmentOptionsExtensions.cs
+++ b/ShippingRates/Helpers/Extensions/ShipmentOptionsExtensions.cs
@@ -1,11 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Runtime.CompilerServices;
-using System.Text;
-
-namespace ShippingRates.Helpers.Extensions
+namespace ShippingRates.Helpers.Extensions
 {
-    public static class ShipmentOptionsExtensions
+    internal static class ShipmentOptionsExtensions
     {
         public static string GetCurrencyCode(this ShipmentOptions options)
         {