diff --git a/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs b/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs
index f8f6306d22..ac84f54e79 100644
--- a/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs
+++ b/src/Platform/Microsoft.Testing.Platform/CommandLine/Parser.cs
@@ -12,7 +12,7 @@ internal static class CommandLineParser
     /// Options parser support:
     ///     * Only - and -- prefix for options https://learn.microsoft.com/dotnet/standard/commandline/syntax#options
     ///     * Multiple option arguments https://learn.microsoft.com/dotnet/standard/commandline/syntax#multiple-arguments
-    ///     * Use a space, '=', or ':' as the delimiter between an option name and its argument
+    ///     * Use '=' or ':' as the delimiter between an option name and its argument. See https://learn.microsoft.com/dotnet/standard/commandline/syntax#option-argument-delimiters
     ///     * escape with \
     ///     * surrounding with ""
     ///     * surrounding with ''
@@ -39,89 +39,65 @@ private static CommandLineParseResult Parse(List<string> args, IEnvironment envi
         List<string> errors = [];
 
         string? currentOption = null;
-        string? currentArg = null;
         string? toolName = null;
         List<string> currentOptionArguments = [];
+        bool isFirstRealArgument = true;
         for (int i = 0; i < args.Count; i++)
         {
-            if (args[i].StartsWith('@') && ResponseFileHelper.TryReadResponseFile(args[i].Substring(1), errors, out string[]? newArguments))
+            string? currentArg = args[i];
+
+            if (currentArg.StartsWith('@') && ResponseFileHelper.TryReadResponseFile(currentArg.Substring(1), errors, out string[]? newArguments))
             {
                 args.InsertRange(i + 1, newArguments);
                 continue;
             }
 
-            bool argumentHandled = false;
-            currentArg = args[i];
+            // If it's the first argument and it doesn't start with - then it's the tool name
+            // TODO: This won't work correctly if the first argument provided is a response file that contains the tool name.
+            if (isFirstRealArgument && currentArg[0] != '-')
+            {
+                toolName = currentArg;
+                isFirstRealArgument = false;
+                continue;
+            }
 
-            while (!argumentHandled)
+            isFirstRealArgument = false;
+
+            // we accept as start for options -- and - all the rest are arguments to the previous option
+            if ((currentArg.Length > 1 && currentArg[0].Equals('-') && !currentArg[1].Equals('-')) ||
+                (currentArg.Length > 2 && currentArg[0].Equals('-') && currentArg[1].Equals('-') && !currentArg[2].Equals('-')))
             {
-                if (currentArg is null)
+                if (currentOption is not null)
                 {
-                    errors.Add(string.Format(CultureInfo.InvariantCulture, PlatformResources.CommandLineParserUnexpectedNullArgument, i));
-                    break;
+                    options.Add(new(currentOption, [.. currentOptionArguments]));
+                    currentOptionArguments.Clear();
                 }
 
-                // we accept as start for options -- and - all the rest are arguments to the previous option
-                if ((args[i].Length > 1 && currentArg[0].Equals('-') && !currentArg[1].Equals('-')) ||
-                    (args[i].Length > 2 && currentArg[0].Equals('-') && currentArg[1].Equals('-') && !currentArg[2].Equals('-')))
+                ParseOptionAndSeparators(currentArg, out currentOption, out currentArg);
+            }
+
+            if (currentArg is not null)
+            {
+                if (currentOption is null)
                 {
-                    if (currentOption is null)
-                    {
-                        ParseOptionAndSeparators(args[i], out currentOption, out currentArg);
-                        argumentHandled = currentArg is null;
-                    }
-                    else
-                    {
-                        options.Add(new(currentOption, [.. currentOptionArguments]));
-                        currentOptionArguments.Clear();
-                        ParseOptionAndSeparators(args[i], out currentOption, out currentArg);
-                        argumentHandled = true;
-                    }
+                    errors.Add(string.Format(CultureInfo.InvariantCulture, PlatformResources.CommandLineParserUnexpectedArgument, args[i]));
                 }
                 else
                 {
-                    // If it's the first argument and it doesn't start with - then it's the tool name
-                    if (i == 0 && !args[0][0].Equals('-'))
-                    {
-                        toolName = currentArg;
-                    }
-                    else if (currentOption is null)
+                    if (TryUnescape(currentArg.Trim(), currentOption, environment, out string? unescapedArg, out string? error))
                     {
-                        errors.Add(string.Format(CultureInfo.InvariantCulture, PlatformResources.CommandLineParserUnexpectedArgument, args[i]));
+                        currentOptionArguments.Add(unescapedArg);
                     }
                     else
                     {
-                        if (TryUnescape(currentArg.Trim(), currentOption, environment, out string? unescapedArg, out string? error))
-                        {
-                            currentOptionArguments.Add(unescapedArg);
-                        }
-                        else
-                        {
-                            errors.Add(error);
-                        }
-
-                        currentArg = null;
+                        errors.Add(error);
                     }
-
-                    argumentHandled = true;
                 }
             }
         }
 
         if (currentOption is not null)
         {
-            if (currentArg is not null)
-            {
-                if (TryUnescape(currentArg.Trim(), currentOption, environment, out string? unescapedArg, out string? error))
-                {
-                    currentOptionArguments.Add(unescapedArg);
-                }
-                else
-                {
-                    errors.Add(error);
-                }
-            }
-
             options.Add(new(currentOption, [.. currentOptionArguments]));
         }
 
@@ -129,7 +105,7 @@ private static CommandLineParseResult Parse(List<string> args, IEnvironment envi
 
         static void ParseOptionAndSeparators(string arg, out string? currentOption, out string? currentArg)
         {
-            (currentOption, currentArg) = arg.IndexOfAny([':', '=', ' ']) switch
+            (currentOption, currentArg) = arg.IndexOfAny([':', '=']) switch
             {
                 -1 => (arg, null),
                 var delimiterIndex => (arg[..delimiterIndex], arg[(delimiterIndex + 1)..]),
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx b/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx
index 87f9857b19..036efd79e9 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/PlatformResources.resx
@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!--
-    Microsoft ResX Schema
-
+  <!-- 
+    Microsoft ResX Schema 
+    
     Version 2.0
-
-    The primary goals of this format is to allow a simple XML format
-    that is mostly human readable. The generation and parsing of the
-    various data types are done through the TypeConverter classes
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
     associated with the data types.
-
+    
     Example:
-
+    
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-
-    There are any number of "resheader" rows that contain simple
+                
+    There are any number of "resheader" rows that contain simple 
     name/value pairs.
-
-    Each data row contains a name, and value. The row also contains a
-    type or mimetype. Type corresponds to a .NET class that support
-    text/value conversion through the TypeConverter architecture.
-    Classes that don't support this are serialized and stored with the
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
     mimetype set.
-
-    The mimetype is used for serialized objects, and tells the
-    ResXResourceReader how to depersist the object. This is currently not
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
     extensible. For a given mimetype the value must be set accordingly:
-
-    Note - application/x-microsoft.net.object.binary.base64 is the format
-    that the ResXResourceWriter will generate, however the reader can
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
     read any of the formats listed below.
-
+    
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-
+    
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with
+    value   : The object must be serialized with 
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array
+    value   : The object must be serialized into a byte array 
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -319,9 +319,6 @@
   <data name="CommandLineParserUnexpectedArgument" xml:space="preserve">
     <value>Unexpected argument {0}</value>
   </data>
-  <data name="CommandLineParserUnexpectedNullArgument" xml:space="preserve">
-    <value>Unexpected null argument at index {0}</value>
-  </data>
   <data name="CommandLineParserUnexpectedSingleQuoteInArgument" xml:space="preserve">
     <value>Unexpected single quote in argument: {0}</value>
   </data>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf
index d69915357b..41efbbe3b5 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.cs.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Neočekávaný argument {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Neočekávaný argument null v indexu {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Neočekávaná jednoduchá uvozovka v argumentu: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf
index 80b922c3a3..6dafbd92ae 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.de.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Unerwartetes Argument {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Unerwartetes NULL-Argument bei Index {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Unerwartetes einfaches Anführungszeichen im Argument: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf
index 2b8f0aaaee..ca22203490 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.es.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Argumento inesperado {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Argumento nulo inesperado en el índice {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Comilla simple inesperada en el argumento: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf
index 4f6119a574..e341f04865 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.fr.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Arguments inattendue {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Argument null inattendu à l’index de recherche{0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Guillemet simple inattendu dans l’argument : {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf
index f1796f9a53..5a0fe9b87c 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.it.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Argomento imprevisto {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Argomento Null imprevisto in corrispondenza dell'indice {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Virgolette singole impreviste nell'argomento: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf
index 3c784e8746..6f402ad9c9 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ja.xlf
@@ -142,11 +142,6 @@
         <target state="translated">予期しない引数 {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">インデックス {0} に予期しない null 引数があります</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">引数に予期しない単一引用符が含まれています: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf
index fad6a7986d..519426f952 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ko.xlf
@@ -142,11 +142,6 @@
         <target state="translated">예기치 않은 인수 {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">인덱스 {0}에 예기치 않은 null 인수가 있습니다.</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">인수 {0}에 예기치 않은 작은따옴표가 있습니다.</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf
index 875395e810..ec53ed7191 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pl.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Nieoczekiwany argument {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Nieoczekiwany argument o wartości null przy indeksie {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Nieoczekiwany pojedynczy cudzysłów w argumencie: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf
index bf2ef2a56f..5a2bc95a8f 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.pt-BR.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Argumento inesperado {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Argumento nulo inesperado no índice {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Aspas simples inesperadas no argumento: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf
index c702e2a59b..30201fcdff 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.ru.xlf
@@ -142,11 +142,6 @@
         <target state="translated">Неожиданный аргумент {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">Неожиданный аргумент, имеющий значение NULL, с индексом {0}</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">Неожиданная одинарная кавычка в аргументе: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf
index 93eb747fa8..36dc259dc6 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.tr.xlf
@@ -142,11 +142,6 @@
         <target state="translated">{0} bağımsız değişkeni beklenmiyordu</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">{0} dizinindeki null bağımsız değişken beklenmiyordu</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">{0} bağımsız değişkeninde tek alıntı beklenmiyor</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf
index 98941bc5ab..08a9beb56e 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hans.xlf
@@ -142,11 +142,6 @@
         <target state="translated">意外的参数 {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">索引 {0} 处出现意外 null 参数</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">参数中出现意外的单引号: {0}</target>
diff --git a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf
index c015e72cf9..a35747c7cb 100644
--- a/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf
+++ b/src/Platform/Microsoft.Testing.Platform/Resources/xlf/PlatformResources.zh-Hant.xlf
@@ -142,11 +142,6 @@
         <target state="translated">未預期的引數 {0}</target>
         <note />
       </trans-unit>
-      <trans-unit id="CommandLineParserUnexpectedNullArgument">
-        <source>Unexpected null argument at index {0}</source>
-        <target state="translated">索引 {0} 中有未預期的 Null 引數</target>
-        <note />
-      </trans-unit>
       <trans-unit id="CommandLineParserUnexpectedSingleQuoteInArgument">
         <source>Unexpected single quote in argument: {0}</source>
         <target state="translated">引數 {0} 中有未預期的單引號</target>
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/ArgumentArityTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/ArgumentArityTests.cs
index c688a2062f..18d10a3281 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/ArgumentArityTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/ArgumentArityTests.cs
@@ -27,7 +27,7 @@ public sealed class ArgumentArityTests
     public async Task ParseAndValidate_WhenOptionWithArityZeroIsCalledWithOneArgument_ReturnsFalse()
     {
         // Arrange
-        string[] args = ["--zeroArgumentsOption arg"];
+        string[] args = ["--zeroArgumentsOption", "arg"];
         CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
 
         // Act
@@ -43,7 +43,7 @@ public async Task ParseAndValidate_WhenOptionWithArityZeroIsCalledWithOneArgumen
     public async Task ParseAndValidate_WhenOptionWithArityExactlyOneIsCalledWithTwoArguments_ReturnsFalse()
     {
         // Arrange
-        string[] args = ["--exactlyOneArgumentsOption arg1", "arg2"];
+        string[] args = ["--exactlyOneArgumentsOption", "arg1", "arg2"];
         CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
 
         // Act
@@ -75,7 +75,7 @@ public async Task ParseAndValidate_WhenOptionWithArityExactlyOneIsCalledWithoutA
     public async Task ParseAndValidate_WhenOptionWithArityZeroOrOneIsCalledWithTwoArguments_ReturnsFalse()
     {
         // Arrange
-        string[] args = ["--zeroOrOneArgumentsOption arg1", "--zeroOrOneArgumentsOption arg2"];
+        string[] args = ["--zeroOrOneArgumentsOption", "arg1", "--zeroOrOneArgumentsOption", "arg2"];
         CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
 
         // Act
@@ -107,7 +107,7 @@ public async Task ParseAndValidate_WhenOptionWithArityOneOrMoreIsCalledWithoutAr
     public async Task ParseAndValidate_WhenOptionsGetsTheExpectedNumberOfArguments_ReturnsTrue()
     {
         // Arrange
-        string[] args = ["--zeroArgumentsOption", "--zeroOrOneArgumentsOption", "--zeroOrMoreArgumentsOption arg2", "--exactlyOneArgumentsOption arg1", "oneOrMoreArgumentsOption arg1"];
+        string[] args = ["--zeroArgumentsOption", "--zeroOrOneArgumentsOption", "--zeroOrMoreArgumentsOption", "arg2", "--exactlyOneArgumentsOption", "arg1", "--oneOrMoreArgumentsOption", "arg1"];
         CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
 
         // Act
@@ -115,8 +115,8 @@ public async Task ParseAndValidate_WhenOptionsGetsTheExpectedNumberOfArguments_R
             _extensionCommandLineOptionsProviders, new Mock<ICommandLineOptions>().Object);
 
         // Assert
-        Assert.IsTrue(result.IsValid);
         Assert.IsNull(result.ErrorMessage);
+        Assert.IsTrue(result.IsValid);
     }
 
     private sealed class ExtensionCommandLineProviderMockOptionsWithDifferentArity : ICommandLineOptionsProvider
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs
index 2e82935009..37ecded06a 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineHandlerTests.cs
@@ -42,6 +42,66 @@ public async Task ParseAndValidateAsync_InvalidCommandLineArguments_ReturnsFalse
         Assert.Contains("Unexpected argument 'a'", result.ErrorMessage);
     }
 
+    [TestMethod]
+    public async Task ParseAndValidateAsync_ValidArgumentWithColonFollowedByValidArgumentWithoutColon_ReturnsTrue()
+    {
+        string[] args = ["--results-directory", "TestResults", "--timeout:60m", "--ignore-exit-code", "8"];
+        CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
+
+        Assert.IsEmpty(parseResult.Errors);
+        Assert.IsFalse(parseResult.HasError);
+
+        Assert.HasCount(3, parseResult.Options);
+
+        Assert.AreEqual("results-directory", parseResult.Options[0].Name);
+        string resultsDirectory = Assert.ContainsSingle(parseResult.Options[0].Arguments);
+        Assert.AreEqual("TestResults", resultsDirectory);
+
+        Assert.AreEqual("timeout", parseResult.Options[1].Name);
+        string timeout = Assert.ContainsSingle(parseResult.Options[1].Arguments);
+        Assert.AreEqual("60m", timeout);
+
+        Assert.AreEqual("ignore-exit-code", parseResult.Options[2].Name);
+        string ignoreExitCode = Assert.ContainsSingle(parseResult.Options[2].Arguments);
+        Assert.AreEqual("8", ignoreExitCode);
+
+        ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(parseResult, _systemCommandLineOptionsProviders,
+            _extensionCommandLineOptionsProviders, new Mock<ICommandLineOptions>().Object);
+
+        Assert.IsNull(result.ErrorMessage);
+        Assert.IsTrue(result.IsValid);
+    }
+
+    [TestMethod]
+    public async Task ParseAndValidateAsync_ValidArgumentWithColonValueIsShort_ReturnsTrue()
+    {
+        string[] args = ["--results-directory", "TestResults", "--ignore-exit-code:8", "--timeout", "60m"];
+        CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
+
+        Assert.IsEmpty(parseResult.Errors);
+        Assert.IsFalse(parseResult.HasError);
+
+        Assert.HasCount(3, parseResult.Options);
+
+        Assert.AreEqual("results-directory", parseResult.Options[0].Name);
+        string resultsDirectory = Assert.ContainsSingle(parseResult.Options[0].Arguments);
+        Assert.AreEqual("TestResults", resultsDirectory);
+
+        Assert.AreEqual("ignore-exit-code", parseResult.Options[1].Name);
+        string ignoreExitCode = Assert.ContainsSingle(parseResult.Options[1].Arguments);
+        Assert.AreEqual("8", ignoreExitCode);
+
+        Assert.AreEqual("timeout", parseResult.Options[2].Name);
+        string timeout = Assert.ContainsSingle(parseResult.Options[2].Arguments);
+        Assert.AreEqual("60m", timeout);
+
+        ValidationResult result = await CommandLineOptionsValidator.ValidateAsync(parseResult, _systemCommandLineOptionsProviders,
+            _extensionCommandLineOptionsProviders, new Mock<ICommandLineOptions>().Object);
+
+        Assert.IsNull(result.ErrorMessage);
+        Assert.IsTrue(result.IsValid);
+    }
+
     [TestMethod]
     public async Task ParseAndValidateAsync_EmptyCommandLineArguments_ReturnsTrue()
     {
@@ -98,7 +158,7 @@ public async Task ParseAndValidateAsync_InvalidOption_ReturnsFalse()
     public async Task ParseAndValidateAsync_InvalidArgumentArity_ReturnsFalse()
     {
         // Arrange
-        string[] args = ["--help arg"];
+        string[] args = ["--help", "arg"];
         CommandLineParseResult parseResult = CommandLineParser.Parse(args, new SystemEnvironment());
 
         // Act
diff --git a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineTests.cs b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineTests.cs
index 74af4bf15c..ab0108e55c 100644
--- a/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineTests.cs
+++ b/test/UnitTests/Microsoft.Testing.Platform.UnitTests/CommandLine/CommandLineTests.cs
@@ -86,7 +86,7 @@ public static string ParserTestDataFormat(MethodInfo methodInfo, object?[]? data
         yield return (15, ["--option1:a"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a"]) }.ToArray(), []));
         yield return (16, ["--option1=a"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a"]) }.ToArray(), []));
         yield return (17, ["--option1=a", "--option1=b"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a"]), new("option1", ["b"]) }.ToArray(), []));
-        yield return (18, ["--option1=a", "--option1 b"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a"]), new("option1", ["b"]) }.ToArray(), []));
+        yield return (18, ["--option1=a", "--option1", "b"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a"]), new("option1", ["b"]) }.ToArray(), []));
         yield return (19, ["--option1=a=a"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a=a"]) }.ToArray(), []));
         yield return (20, ["--option1=a:a"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a:a"]) }.ToArray(), []));
         yield return (21, ["--option1:a=a"], null, new CommandLineParseResultWrapper(null, new List<CommandLineParseOption> { new("option1", ["a=a"]) }.ToArray(), []));