diff --git a/DigitalData.Core.Tests/DTO/BaseDtoTest.cs b/DigitalData.Core.Tests/DTO/BaseDtoTest.cs
index 14bf03a..beaf72e 100644
--- a/DigitalData.Core.Tests/DTO/BaseDtoTest.cs
+++ b/DigitalData.Core.Tests/DTO/BaseDtoTest.cs
@@ -75,5 +75,21 @@ namespace DigitalData.Core.Tests.DTO
 
 			Assert.IsFalse(dto1 != dto2);
 		}
+
+		[Test]
+		public void EntityWithSameIdShouldBeContained()
+		{
+			IEnumerable<SampleDto> dtos = new List<SampleDto>() { new(1), new(2) };
+			var dto = new SampleDto(1);
+			Assert.That(dtos, Does.Contain(dto));
+		}
+
+		[Test]
+		public void EntityWithSameIdShouldBeNotContained()
+		{
+			IEnumerable<SampleDto> dtos = new List<SampleDto>() { new(1), new(2) };
+			var dto = new SampleDto(3);
+			Assert.That(dtos, !Does.Contain(dto));
+		}
 	}
 }
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