diff --git a/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs b/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs
index fd8cfbc4..57a6157f 100644
--- a/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs
+++ b/src/xunit.analyzers.tests/Analyzers/X1000/InlineDataMustMatchTheoryParametersTests.cs
@@ -313,6 +313,24 @@ public void TestMethod(byte[] input) { }
 
 			await Verify.VerifyAnalyzer(source);
 		}
+
+		// https://github.com/xunit/xunit/issues/3000
+		[Fact]
+		public async Task DecimalValue()
+		{
+			var source = /* lang=c#-test */ """
+				using Xunit;
+
+				public sealed class ReproClass {
+					[Theory]
+					[InlineData({|CS0182:0.1m|})]
+					public void ReproMethod(decimal m)
+					{ }
+				}
+				""";
+
+			await Verify.VerifyAnalyzer(source);
+		}
 	}
 
 	public class X1009_TooFewValues
diff --git a/src/xunit.analyzers/X1000/InlineDataMustMatchTheoryParameters.cs b/src/xunit.analyzers/X1000/InlineDataMustMatchTheoryParameters.cs
index 562a359b..ba1e656b 100644
--- a/src/xunit.analyzers/X1000/InlineDataMustMatchTheoryParameters.cs
+++ b/src/xunit.analyzers/X1000/InlineDataMustMatchTheoryParameters.cs
@@ -97,6 +97,11 @@ public override void AnalyzeCompilation(
 					var parameter = method.Parameters[paramIdx];
 					var value = values[valueIdx];
 
+					// If the value isn't legal (malformed or illegal type), then just skip validation and let
+					// the compiler report the problem.
+					if (value.Kind == TypedConstantKind.Error)
+						continue;
+
 					// If the parameter type is object, everything is compatible, though we still need to check for nullability
 					if (SymbolEqualityComparer.Default.Equals(parameter.Type, compilation.ObjectType)
 						&& (!value.IsNull || parameter.Type.NullableAnnotation != NullableAnnotation.NotAnnotated))