diff --git a/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue340Tests.cs b/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue340Tests.cs
index f49273f94..5a3dc5a14 100644
--- a/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue340Tests.cs
+++ b/test/ExtendedXmlSerializer.Tests.ReportedIssues/Issue340Tests.cs
@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using Xunit;
+
 // ReSharper disable PossibleMultipleEnumeration
 
 namespace ExtendedXmlSerializer.Tests.ReportedIssues
@@ -14,7 +15,7 @@ public sealed class Issue340Tests
 		[Fact]
 		void Verify()
 		{
-			var instance = new Subject { Contents = new[] {"Hello", "World!"}.Select(x => x) };
+			var instance = new Subject {Contents = new[] {"Hello", "World!"}.Select(x => x)};
 			new ConfigurationContainer().WithEnumerableSupport()
 			                            .ForTesting()
 			                            .Cycle(instance)
@@ -45,6 +46,18 @@ void VerifyImmutable()
 			                            .BeEquivalentTo(instance);
 		}
 
+		[Fact]
+		void VerifyImmutableEnumerable()
+		{
+			var instance = new ImmutableSubject(new[] {"Hello", "World!"}.Select(x => x));
+			var subject = new ConfigurationContainer().EnableParameterizedContent()
+			                                          .WithEnumerableSupport()
+			                                          .ForTesting()
+			                                          .Cycle(instance);
+			subject.Should().BeEquivalentTo(instance);
+			subject.Contents.Should().BeAssignableTo<List<string>>();
+		}
+
 		sealed class Subject
 		{
 			public IEnumerable<string> Contents { [UsedImplicitly] get; set; }