diff --git a/src/FluentAssertions.Analyzers.Tests/DiagnosticVerifier.cs b/src/FluentAssertions.Analyzers.Tests/DiagnosticVerifier.cs
index 0dcd523a..342b8e76 100644
--- a/src/FluentAssertions.Analyzers.Tests/DiagnosticVerifier.cs
+++ b/src/FluentAssertions.Analyzers.Tests/DiagnosticVerifier.cs
@@ -18,6 +18,8 @@
 
 using XunitAssert = Xunit.Assert;
 using System.Net.Http;
+using System.Collections.Concurrent;
+using System.Collections.ObjectModel;
 
 namespace FluentAssertions.Analyzers.Tests
 {
@@ -40,6 +42,8 @@ static DiagnosticVerifier()
                 typeof(AssertionExtensions), // FluentAssertions
                 typeof(HttpRequestMessage), // System.Net.Http
                 typeof(ImmutableArray), // System.Collections.Immutable
+                typeof(ConcurrentBag<>), // System.Collections.Concurrent
+                typeof(ReadOnlyDictionary<,>), // System.ObjectModel
                 typeof(Microsoft.VisualStudio.TestTools.UnitTesting.Assert), // MsTest
                 typeof(XunitAssert), // Xunit
             }.Select(type => type.GetTypeInfo().Assembly.Location)
diff --git a/src/FluentAssertions.Analyzers.Tests/FluentAssertions.Analyzers.Tests.csproj b/src/FluentAssertions.Analyzers.Tests/FluentAssertions.Analyzers.Tests.csproj
index be556a30..90441766 100644
--- a/src/FluentAssertions.Analyzers.Tests/FluentAssertions.Analyzers.Tests.csproj
+++ b/src/FluentAssertions.Analyzers.Tests/FluentAssertions.Analyzers.Tests.csproj
@@ -15,7 +15,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
     <PackageReference Include="MSTest.TestAdapter" Version="3.1.1" />
     <PackageReference Include="MSTest.TestFramework" Version="3.1.1" />
-    <PackageReference Include="xunit.assert" Version="2.4.2" />
+    <PackageReference Include="xunit.assert" Version="2.5.1" />
   </ItemGroup>
 
   <ItemGroup>