diff --git a/src/libraries/System.Text.RegularExpressions/gen/UpgradeToRegexGeneratorCodeFixer.cs b/src/libraries/System.Text.RegularExpressions/gen/UpgradeToRegexGeneratorCodeFixer.cs
index cdeefeae3d441..a5c4df1d4b389 100644
--- a/src/libraries/System.Text.RegularExpressions/gen/UpgradeToRegexGeneratorCodeFixer.cs
+++ b/src/libraries/System.Text.RegularExpressions/gen/UpgradeToRegexGeneratorCodeFixer.cs
@@ -193,13 +193,13 @@ private static async Task<Document> ConvertToSourceGenerator(Document document,
             // Try to get the pattern and RegexOptions values out from the diagnostic's property bag.
             if (operation is IObjectCreationOperation objectCreationOperation) // When using the Regex constructors
             {
-                patternValue = GetNode((objectCreationOperation).Arguments, properties, UpgradeToRegexGeneratorAnalyzer.PatternIndexName, generator, useOptionsMemberExpression: false, compilation);
-                regexOptionsValue = GetNode((objectCreationOperation).Arguments, properties, UpgradeToRegexGeneratorAnalyzer.RegexOptionsIndexName, generator, useOptionsMemberExpression: true, compilation);
+                patternValue = GetNode((objectCreationOperation).Arguments, properties, UpgradeToRegexGeneratorAnalyzer.PatternIndexName, generator, useOptionsMemberExpression: false, compilation, cancellationToken);
+                regexOptionsValue = GetNode((objectCreationOperation).Arguments, properties, UpgradeToRegexGeneratorAnalyzer.RegexOptionsIndexName, generator, useOptionsMemberExpression: true, compilation, cancellationToken);
             }
             else if (operation is IInvocationOperation invocation) // When using the Regex static methods.
             {
-                patternValue = GetNode(invocation.Arguments, properties, UpgradeToRegexGeneratorAnalyzer.PatternIndexName, generator, useOptionsMemberExpression: false, compilation);
-                regexOptionsValue = GetNode(invocation.Arguments, properties, UpgradeToRegexGeneratorAnalyzer.RegexOptionsIndexName, generator, useOptionsMemberExpression: true, compilation);
+                patternValue = GetNode(invocation.Arguments, properties, UpgradeToRegexGeneratorAnalyzer.PatternIndexName, generator, useOptionsMemberExpression: false, compilation, cancellationToken);
+                regexOptionsValue = GetNode(invocation.Arguments, properties, UpgradeToRegexGeneratorAnalyzer.RegexOptionsIndexName, generator, useOptionsMemberExpression: true, compilation, cancellationToken);
             }
 
             // Generate the new static partial method
@@ -260,7 +260,7 @@ static IEnumerable<ISymbol> GetAllMembers(ITypeSymbol? symbol)
             }
 
             // Helper method that looks int the properties bag for the index of the passed in propertyname, and then returns that index from the args parameter.
-            static SyntaxNode? GetNode(ImmutableArray<IArgumentOperation> args, ImmutableDictionary<string, string?> properties, string propertyName, SyntaxGenerator generator, bool useOptionsMemberExpression, Compilation compilation)
+            static SyntaxNode? GetNode(ImmutableArray<IArgumentOperation> args, ImmutableDictionary<string, string?> properties, string propertyName, SyntaxGenerator generator, bool useOptionsMemberExpression, Compilation compilation, CancellationToken cancellationToken)
             {
                 int? index = TryParseInt32(properties, propertyName);
                 if (index == null)
@@ -276,7 +276,7 @@ static IEnumerable<ISymbol> GetAllMembers(ITypeSymbol? symbol)
                 {
                     RegexOptions options = (RegexOptions)(int)args[index.Value].Value.ConstantValue.Value;
                     string optionsLiteral = Literal(options);
-                    return SyntaxFactory.ParseExpression(optionsLiteral).SyntaxTree.GetRoot();
+                    return SyntaxFactory.ParseExpression(optionsLiteral).SyntaxTree.GetRoot(cancellationToken);
                 }
             }
 
diff --git a/src/libraries/System.Text.RegularExpressions/tests/UnitTests/CSharpCodeFixVerifier`2.cs b/src/libraries/System.Text.RegularExpressions/tests/UnitTests/CSharpCodeFixVerifier`2.cs
index 0cbda942d8cc0..83ce1218adb7c 100644
--- a/src/libraries/System.Text.RegularExpressions/tests/UnitTests/CSharpCodeFixVerifier`2.cs
+++ b/src/libraries/System.Text.RegularExpressions/tests/UnitTests/CSharpCodeFixVerifier`2.cs
@@ -34,10 +34,10 @@ public static DiagnosticResult Diagnostic(DiagnosticDescriptor descriptor)
 
         /// <inheritdoc cref="CodeFixVerifier{TAnalyzer, TCodeFix, TTest, TVerifier}.VerifyAnalyzerAsync(string, DiagnosticResult[])"/>
         public static async Task VerifyAnalyzerAsync(string source, params DiagnosticResult[] expected)
-            => await VerifyAnalyzerAsync(source, ReferenceAssemblies.Net.Net70, usePreviewLanguageVersion: true, expected);
+            => await VerifyAnalyzerAsync(source, null, usePreviewLanguageVersion: true, expected);
 
         /// <inheritdoc cref="CodeFixVerifier{TAnalyzer, TCodeFix, TTest, TVerifier}.VerifyAnalyzerAsync(string, DiagnosticResult[])"/>
-        public static async Task VerifyAnalyzerAsync(string source, ReferenceAssemblies references, bool usePreviewLanguageVersion, params DiagnosticResult[] expected)
+        public static async Task VerifyAnalyzerAsync(string source, ReferenceAssemblies? references, bool usePreviewLanguageVersion, params DiagnosticResult[] expected)
         {
             Test test = new Test(references, usePreviewLanguageVersion, numberOfIterations: 1)
             {
@@ -59,7 +59,7 @@ public static async Task VerifyCodeFixAsync(string source, DiagnosticResult expe
         /// <inheritdoc cref="CodeFixVerifier{TAnalyzer, TCodeFix, TTest, TVerifier}.VerifyCodeFixAsync(string, DiagnosticResult[], string)"/>
         public static async Task VerifyCodeFixAsync(string source, DiagnosticResult[] expected, string fixedSource, int numberOfIterations = 1)
         {
-            Test test = new Test(ReferenceAssemblies.Net.Net70, usePreviewLanguageVersion: true, numberOfIterations)
+            Test test = new Test(null, usePreviewLanguageVersion: true, numberOfIterations)
             {
                 TestCode = source,
                 FixedCode = fixedSource,
@@ -71,12 +71,22 @@ public static async Task VerifyCodeFixAsync(string source, DiagnosticResult[] ex
 
         public class Test : CSharpCodeFixTest<TAnalyzer, TCodeFix, XUnitVerifier>
         {
-            public Test(ReferenceAssemblies references, bool usePreviewLanguageVersion, int numberOfIterations)
+            public Test(ReferenceAssemblies? references, bool usePreviewLanguageVersion, int numberOfIterations)
             {
                 // Code Fixer generates partial methods that will need to use the source generator to be filled.
                 this.CompilerDiagnostics = CompilerDiagnostics.None;
 
-                ReferenceAssemblies = references;
+                if (references != null)
+                {
+                    ReferenceAssemblies = references;
+                }
+                else
+                {
+                    // Clear out the default reference assemblies. We explicitly add references from the live ref pack,
+                    // so we don't want the Roslyn test infrastructure to resolve/add any default reference assemblies
+                    ReferenceAssemblies = new ReferenceAssemblies(string.Empty);
+                    TestState.AdditionalReferences.AddRange(SourceGenerators.Tests.LiveReferencePack.GetMetadataReferences());
+                }
 
                 NumberOfFixAllIterations = numberOfIterations;
 
diff --git a/src/libraries/System.Text.RegularExpressions/tests/UnitTests/System.Text.RegularExpressions.Unit.Tests.csproj b/src/libraries/System.Text.RegularExpressions/tests/UnitTests/System.Text.RegularExpressions.Unit.Tests.csproj
index 6129eab9b8e1a..77f1ad9eb8ade 100644
--- a/src/libraries/System.Text.RegularExpressions/tests/UnitTests/System.Text.RegularExpressions.Unit.Tests.csproj
+++ b/src/libraries/System.Text.RegularExpressions/tests/UnitTests/System.Text.RegularExpressions.Unit.Tests.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <!-- xUnit2008 is about regexes and isn't appropriate in the test project for regexes -->
     <!-- SYSLIB0036 is about obsoletion of regex members -->
@@ -9,6 +9,7 @@
     <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <DefineConstants>$(DefineConstants);DEBUG</DefineConstants> <!-- always define debug, even in release builds -->
+    <TestRunRequiresLiveRefPack>true</TestRunRequiresLiveRefPack>
   </PropertyGroup>
   <ItemGroup>
     <DefaultReferenceExclusion Include="System.Text.RegularExpressions" />
@@ -48,6 +49,7 @@
     <Compile Include="..\..\src\System\Collections\HashtableExtensions.cs" Link="Production\HashtableExtensions.cs" />
     <Compile Include="..\..\gen\UpgradeToRegexGeneratorAnalyzer.cs" Link="Production\UpgradeToRegexGeneratorAnalyzer.cs" />
     <Compile Include="..\..\gen\UpgradeToRegexGeneratorCodeFixer.cs" Link="Production\UpgradeToRegexGeneratorCodeFixer.cs" />
+    <Compile Include="$(CommonTestPath)SourceGenerators\LiveReferencePack.cs" Link="Common\SourceGenerators\LiveReferencePack.cs" />
 
     <!-- Code used as stubs to avoid pulling in further code from System.Text.RegularExpressions -->
     <Compile Include="Stubs.cs" />
@@ -55,6 +57,6 @@
 
     <!-- References required for the Analyzer tests -->
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="$(MicrosoftCodeAnalysisVersion_4_0)" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing.XUnit" Version="1.1.2-beta1.22255.1" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing.XUnit" Version="$(CompilerPlatformTestingVersion)" />
   </ItemGroup>
 </Project>
diff --git a/src/libraries/System.Text.RegularExpressions/tests/UnitTests/UpgradeToRegexGeneratorAnalyzerTests.cs b/src/libraries/System.Text.RegularExpressions/tests/UnitTests/UpgradeToRegexGeneratorAnalyzerTests.cs
index 757b70d229bad..dc123275c84f5 100644
--- a/src/libraries/System.Text.RegularExpressions/tests/UnitTests/UpgradeToRegexGeneratorAnalyzerTests.cs
+++ b/src/libraries/System.Text.RegularExpressions/tests/UnitTests/UpgradeToRegexGeneratorAnalyzerTests.cs
@@ -119,7 +119,7 @@ public static void Main(string[] args)
     }
 }";
 
-            await VerifyCS.VerifyAnalyzerAsync(test, ReferenceAssemblies.Net.Net70, usePreviewLanguageVersion: false);
+            await VerifyCS.VerifyAnalyzerAsync(test, null, usePreviewLanguageVersion: false);
         }
 
         public static IEnumerable<object[]> ConstantPatternTestData()
@@ -503,8 +503,7 @@ public static void Main(string[] args)
 
             foreach (bool includeRegexOptions in new[] { true, false })
             {
-                // Can't test EnumerateMatches yet since the reference assemblies used by the test infrastructure doesn't have that API yet.
-                foreach (string methodName in new[] { "Count", /* "EnumerateMatches" ,*/ "IsMatch", "Match", "Matches", "Split" })
+                foreach (string methodName in new[] { "Count", "EnumerateMatches" , "IsMatch", "Match", "Matches", "Split" })
                 {
                     if (includeRegexOptions)
                     {