diff --git a/sdk/src/Core/Amazon.Runtime/ParameterCollection.cs b/sdk/src/Core/Amazon.Runtime/ParameterCollection.cs
index 5e7e678c244e..f1b82d285794 100644
--- a/sdk/src/Core/Amazon.Runtime/ParameterCollection.cs
+++ b/sdk/src/Core/Amazon.Runtime/ParameterCollection.cs
@@ -77,7 +77,7 @@ public List<KeyValuePair<string,string>> GetSortedParametersList()
             return GetParametersEnumerable().ToList();
         }
 
-        private IEnumerable<KeyValuePair<string, string>> GetParametersEnumerable()
+        internal IEnumerable<KeyValuePair<string, string>> GetParametersEnumerable()
         {
             foreach (var kvp in this)
             {
diff --git a/sdk/src/Core/Amazon.Util/AWSSDKUtils.cs b/sdk/src/Core/Amazon.Util/AWSSDKUtils.cs
index 9e45563d1ee6..a9011bff0fde 100644
--- a/sdk/src/Core/Amazon.Util/AWSSDKUtils.cs
+++ b/sdk/src/Core/Amazon.Util/AWSSDKUtils.cs
@@ -302,26 +302,20 @@ public static byte[] GetRequestPayloadBytes(IRequest request, bool? usesQueryStr
          */
         internal static string GetParametersAsString(ParameterCollection parameterCollection)
         {
-            var sortedParameters = parameterCollection.GetSortedParametersList();
-
-            StringBuilder data = new StringBuilder(512);
-            foreach (var kvp in sortedParameters)
+            var parameterBuilder = new ValueStringBuilder(512);
+            foreach (var kvp in parameterCollection.GetParametersEnumerable())
             {
-                var key = kvp.Key;
                 var value = kvp.Value;
-                if (value != null)
-                {
-                    data.Append(key);
-                    data.Append('=');
-                    data.Append(AWSSDKUtils.UrlEncode(value, false));
-                    data.Append('&');
-                }
+                if (value == null)
+                    continue;
+                parameterBuilder.Append(kvp.Key);
+                parameterBuilder.Append('=');
+                parameterBuilder.Append(AWSSDKUtils.UrlEncode(value, false));
+                parameterBuilder.Append('&');
             }
-            string result = data.ToString();
-            if (result.Length == 0)
-                return string.Empty;
 
-            return result.Remove(result.Length - 1);
+            var length = parameterBuilder.Length;
+            return length == 0 ? string.Empty : parameterBuilder.ToString(0, length - 1);
         }
 
         /// <summary>
diff --git a/sdk/test/NetStandard/UnitTests/Core/AWSSDKUtilsTests.cs b/sdk/test/NetStandard/UnitTests/Core/AWSSDKUtilsTests.cs
index 1513b21f6920..4e1f82a08b03 100644
--- a/sdk/test/NetStandard/UnitTests/Core/AWSSDKUtilsTests.cs
+++ b/sdk/test/NetStandard/UnitTests/Core/AWSSDKUtilsTests.cs
@@ -1,5 +1,7 @@
-using Amazon.Util;
+using System.Collections.Generic;
+using Amazon.Util;
 using System.Text;
+using Amazon.Runtime.Internal;
 using Xunit;
 
 namespace UnitTests.NetStandard.Core
@@ -7,6 +9,22 @@ namespace UnitTests.NetStandard.Core
     [Trait("Category", "Core")]
     public class AWSSDKUtilsTests
     {
+        [Fact]
+        public void GetParametersAsString()
+        {
+            var parameters = new ParameterCollection
+            {
+                { "key1", "value1" },
+                { "key2", "value2" },
+                { "key3", new List<string> { "value3", "value4" } },
+                { "key4", new List<double> { 1.1, 2.1 } }
+            };
+
+            var parametersString = AWSSDKUtils.GetParametersAsString(parameters);
+
+            Assert.Equal("key1=value1&key2=value2&key3=value3&key3=value4&key4=1.1&key4=2.1", parametersString);
+        }
+
         [Fact]
         public void ToHexUppercase()
         {