diff --git a/src/Amazon.Core/Models/AwsClient.cs b/src/Amazon.Core/Models/AwsClient.cs
index 4dabb4cb..fa510b60 100755
--- a/src/Amazon.Core/Models/AwsClient.cs
+++ b/src/Amazon.Core/Models/AwsClient.cs
@@ -16,12 +16,24 @@ public abstract class AwsClient
         protected readonly IAwsCredential credential;
 
         public AwsClient(AwsService service, AwsRegion region, IAwsCredential credential)
+            : this(service, region, credential, (string?)null) { }
+
+        public AwsClient(AwsService service, AwsRegion region, IAwsCredential credential, HttpClient httpClient)
+            : this(service, region, credential, httpClient, null) { }
+
+        public AwsClient(AwsService service, AwsRegion region, IAwsCredential credential, HttpClient httpClient, string? endpoint)
+            : this(service, region, credential, endpoint)
+        {
+            this.httpClient = httpClient ?? throw new ArgumentNullException(nameof(httpClient));
+        }
+
+        public AwsClient(AwsService service, AwsRegion region, IAwsCredential credential, string? endpoint)
         {
             this.service    = service    ?? throw new ArgumentNullException(nameof(service));
             Region          = region     ?? throw new ArgumentNullException(nameof(region));
             this.credential = credential ?? throw new ArgumentNullException(nameof(credential));
 
-            Endpoint = $"https://{service.Name}.{region.Name}.amazonaws.com/";
+            Endpoint = endpoint ?? $"https://{service.Name}.{region.Name}.amazonaws.com/";
 
             this.httpClient = new HttpClient(new HttpClientHandler {
                 AutomaticDecompression = DecompressionMethods.GZip
@@ -33,15 +45,7 @@ public AwsClient(AwsService service, AwsRegion region, IAwsCredential credential
             };
         }
 
-        public AwsClient(AwsService service, AwsRegion region, IAwsCredential credential, HttpClient httpClient)
-        {
-            this.service    = service ?? throw new ArgumentNullException(nameof(service));
-            Region          = region ?? throw new ArgumentNullException(nameof(region));
-            this.credential = credential ?? throw new ArgumentNullException(nameof(credential));
-            this.httpClient = httpClient ?? throw new ArgumentNullException(nameof(httpClient));
-
-            Endpoint = $"https://{service.Name}.{region.Name}.amazonaws.com/";
-        }
+        
 
         public string Endpoint { get; }
 
diff --git a/src/Amazon.DynamoDb/DynamoDbClient.cs b/src/Amazon.DynamoDb/DynamoDbClient.cs
index 79bf5bb7..e41f9877 100755
--- a/src/Amazon.DynamoDb/DynamoDbClient.cs
+++ b/src/Amazon.DynamoDb/DynamoDbClient.cs
@@ -19,7 +19,10 @@ public sealed class DynamoDbClient : AwsClient
         };
 
         public DynamoDbClient(AwsRegion region, IAwsCredential credential)
-            : base(AwsService.DynamoDb, region, credential)
+            : this(region, credential, null) { }
+
+        public DynamoDbClient(AwsRegion region, IAwsCredential credential, string? endpoint)
+            : base(AwsService.DynamoDb, region, credential, endpoint)
         {
             httpClient.Timeout = TimeSpan.FromSeconds(10);
         }