diff --git a/src/Faithlife.DataAnnotations/ValidateObjectAttribute.cs b/src/Faithlife.DataAnnotations/ValidateObjectAttribute.cs
index dffc930..609368a 100644
--- a/src/Faithlife.DataAnnotations/ValidateObjectAttribute.cs
+++ b/src/Faithlife.DataAnnotations/ValidateObjectAttribute.cs
@@ -21,6 +21,6 @@ public sealed class ValidateObjectAttribute : ValidationAttribute
 		var innerErrorMessage = string.Join(" ", validationResults.Select(x => x.ErrorMessage).Where(x => x is not null));
 		return new ValidationResult(
 			errorMessage: $"{FormatErrorMessage(validationContext.DisplayName)}{(innerErrorMessage.Length == 0 ? "" : $" ({innerErrorMessage})")}",
-			memberNames: validationContext.MemberName is { } memberName ? new[] { memberName } : null);
+			memberNames: validationContext.MemberName is { } memberName ? [memberName] : null);
 	}
 }
diff --git a/tests/Faithlife.DataAnnotations.Tests/ValidateObjectAttributeTests.cs b/tests/Faithlife.DataAnnotations.Tests/ValidateObjectAttributeTests.cs
new file mode 100644
index 0000000..f52fd15
--- /dev/null
+++ b/tests/Faithlife.DataAnnotations.Tests/ValidateObjectAttributeTests.cs
@@ -0,0 +1,36 @@
+using System.ComponentModel.DataAnnotations;
+using NUnit.Framework;
+
+namespace Faithlife.DataAnnotations.Tests;
+
+public sealed class ValidateObjectAttributeTests
+{
+	[Test]
+	public void ValidateRecursive()
+	{
+		var invalid = new ValidatableDto();
+		var validatable = new ValidatableDto { Required = "x", Validatable = invalid };
+
+		var results = ValidatorUtility.GetValidationResults(validatable);
+		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Validatable)));
+		Assert.That(results.Single().ErrorMessage, Is.EqualTo("The field Validatable is invalid. (The Required field is required.)"));
+
+		validatable.Validatable = new ValidatableDto { Required = "x", Validatable = invalid };
+		results = ValidatorUtility.GetValidationResults(validatable);
+		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Validatable)));
+		Assert.That(results.Single().ErrorMessage, Is.EqualTo("The field Validatable is invalid. (The field Validatable is invalid. (The Required field is required.))"));
+
+		validatable.Validatable.Validatable = new ValidatableDto { Required = "x" };
+		results = ValidatorUtility.GetValidationResults(validatable);
+		Assert.That(results, Is.Empty);
+	}
+
+	private sealed class ValidatableDto
+	{
+		[Required]
+		public string? Required { get; set; }
+
+		[ValidateObject]
+		public ValidatableDto? Validatable { get; set; }
+	}
+}
diff --git a/tests/Faithlife.DataAnnotations.Tests/ValidatorTests.cs b/tests/Faithlife.DataAnnotations.Tests/ValidatorTests.cs
index 8eaf976..f62a8a2 100644
--- a/tests/Faithlife.DataAnnotations.Tests/ValidatorTests.cs
+++ b/tests/Faithlife.DataAnnotations.Tests/ValidatorTests.cs
@@ -27,50 +27,35 @@ public void ValidateRequired()
 		var validatable = new ValidatableDto();
 
 		var results = ValidatorUtility.GetValidationResults(validatable);
-		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Required)));
+		AssertFieldIsRequired(results.Single());
 		var exception = Assert.Throws<ValidationException>(() => ValidatorUtility.Validate(validatable));
-		Assert.That(exception!.ValidationResult.MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Required)));
+		AssertFieldIsRequired(exception!.ValidationResult);
 
 		validatable.Required = "";
 		results = ValidatorUtility.GetValidationResults(validatable);
-		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Required)));
+		AssertFieldIsRequired(results.Single());
 		Assert.Throws<ValidationException>(() => ValidatorUtility.Validate(validatable));
 
 		validatable.Required = " ";
 		results = ValidatorUtility.GetValidationResults(validatable);
-		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Required)));
+		AssertFieldIsRequired(results.Single());
 		Assert.Throws<ValidationException>(() => ValidatorUtility.Validate(validatable));
 
 		validatable.Required = "x";
 		results = ValidatorUtility.GetValidationResults(validatable);
 		Assert.That(results, Is.Empty);
 		ValidatorUtility.Validate(validatable);
-	}
-
-	[Test]
-	public void ValidateRecursive()
-	{
-		var invalid = new ValidatableDto();
-		var validatable = new ValidatableDto { Required = "x", Validatable = invalid };
-
-		var results = ValidatorUtility.GetValidationResults(validatable);
-		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Validatable)));
 
-		validatable.Validatable = new ValidatableDto { Required = "x", Validatable = invalid };
-		results = ValidatorUtility.GetValidationResults(validatable);
-		Assert.That(results.Single().MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Validatable)));
-
-		validatable.Validatable.Validatable = new ValidatableDto { Required = "x" };
-		results = ValidatorUtility.GetValidationResults(validatable);
-		Assert.That(results, Is.Empty);
+		void AssertFieldIsRequired(ValidationResult result)
+		{
+			Assert.That(result.MemberNames.Single(), Is.EqualTo(nameof(ValidatableDto.Required)));
+			Assert.That(result.ErrorMessage, Is.EqualTo("The Required field is required."));
+		}
 	}
 
 	private sealed class ValidatableDto
 	{
 		[Required]
 		public string? Required { get; set; }
-
-		[ValidateObject]
-		public ValidatableDto? Validatable { get; set; }
 	}
 }