diff --git a/src/xunit.analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializable.cs b/src/xunit.analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializable.cs
index aab5e86e..25b898df 100644
--- a/src/xunit.analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializable.cs
+++ b/src/xunit.analyzers/X1000/TheoryDataTypeArgumentsShouldBeSerializable.cs
@@ -214,7 +214,10 @@ public IEnumerable<ITypeSymbol> FindTypeArguments(
 			string name,
 			AttributeData memberDataAttribute)
 		{
-			var arguments = memberDataAttribute.ConstructorArguments[1].Values;
+			var arguments =
+				memberDataAttribute.ConstructorArguments.Length > 1
+					? memberDataAttribute.ConstructorArguments[1].Values
+					: ImmutableArray<TypedConstant>.Empty;
 			var method = GetCompatibleMethod(type, name, arguments);
 
 			if (method is not null && method.IsStatic)