diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/join-string.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/join-string.cs
index 80da5e379..62282a8da 100644
--- a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/join-string.cs
+++ b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/join-string.cs
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 using System;
@@ -90,7 +90,7 @@ namespace Microsoft.PowerShell.Commands.Utility
         /// Gets or sets the input object to join into text.
         /// </summary>
         [Parameter(ValueFromPipeline = true)]
-        public PSObject InputObject { get; set; }
+        public PSObject[] InputObject { get; set; }
 
         /// <inheritdoc />
         protected override void BeginProcessing()
@@ -106,40 +106,46 @@ namespace Microsoft.PowerShell.Commands.Utility
         /// <inheritdoc />
         protected override void ProcessRecord()
         {
-            if (InputObject != null && InputObject != AutomationNull.Value)
+            if (InputObject != null)
             {
-                var inputValue = Property == null
-                                    ? InputObject
-                                    : Property.GetValues(InputObject, false, true).FirstOrDefault()?.Result;
+                foreach (PSObject inputObject in InputObject)
+                {
+                    if (inputObject != null && inputObject != AutomationNull.Value)
+                    {
+                        var inputValue = Property == null
+                                            ? inputObject
+                                            : Property.GetValues(inputObject, false, true).FirstOrDefault()?.Result;
 
-                // conversion to string always succeeds.
-                if (!LanguagePrimitives.TryConvertTo<string>(inputValue, _cultureInfo, out var stringValue))
-                {
-                    throw new PSInvalidCastException("InvalidCastFromAnyTypeToString", ExtendedTypeSystem.InvalidCastCannotRetrieveString, null);
-                }
+                        // conversion to string always succeeds.
+                        if (!LanguagePrimitives.TryConvertTo<string>(inputValue, _cultureInfo, out var stringValue))
+                        {
+                            throw new PSInvalidCastException("InvalidCastFromAnyTypeToString", ExtendedTypeSystem.InvalidCastCannotRetrieveString, null);
+                        }
 
-                if (_firstInputObject)
-                {
-                    _firstInputObject = false;
-                }
-                else
-                {
-                    _outputBuilder.Append(Separator);
-                }
+                        if (_firstInputObject)
+                        {
+                            _firstInputObject = false;
+                        }
+                        else
+                        {
+                            _outputBuilder.Append(Separator);
+                        }
 
-                if (_quoteChar != char.MinValue)
-                {
-                    _outputBuilder.Append(_quoteChar);
-                    _outputBuilder.Append(stringValue);
-                    _outputBuilder.Append(_quoteChar);
-                }
-                else if (string.IsNullOrEmpty(FormatString))
-                {
-                    _outputBuilder.Append(stringValue);
-                }
-                else
-                {
-                    _outputBuilder.AppendFormat(_cultureInfo, FormatString, inputValue);
+                        if (_quoteChar != char.MinValue)
+                        {
+                            _outputBuilder.Append(_quoteChar);
+                            _outputBuilder.Append(stringValue);
+                            _outputBuilder.Append(_quoteChar);
+                        }
+                        else if (string.IsNullOrEmpty(FormatString))
+                        {
+                            _outputBuilder.Append(stringValue);
+                        }
+                        else
+                        {
+                            _outputBuilder.AppendFormat(_cultureInfo, FormatString, inputValue);
+                        }
+                    }
                 }
             }
         }
diff --git a/test/powershell/Modules/Microsoft.PowerShell.Utility/Join-String.Tests.ps1 b/test/powershell/Modules/Microsoft.PowerShell.Utility/Join-String.Tests.ps1
index f4dae19a1..20829d621 100644
--- a/test/powershell/Modules/Microsoft.PowerShell.Utility/Join-String.Tests.ps1
+++ b/test/powershell/Modules/Microsoft.PowerShell.Utility/Join-String.Tests.ps1
@@ -11,6 +11,12 @@ Describe "Join-String" -Tags "CI" {
         { Join-String -InputObject $testObject } | Should -Not -Throw
     }
 
+    It "'Input | Join-String' should be equal to 'Join-String -InputObject Input'" {
+        $result1 = $testObject | Join-String
+        $result2 = Join-String -InputObject $testObject
+        $result1 | Should -BeExactly $result2
+    }
+
     It "Should return a single string" {
         $actual = $testObject | Join-String