diff --git a/Interpreter.cs b/Interpreter.cs
index a1ba45a..6edb57d 100644
--- a/Interpreter.cs
+++ b/Interpreter.cs
@@ -63,16 +63,6 @@ public class Env
 
 public class Interpreter : AST.IExprVisitor<Env, object>
 {
-	private static void checkTypesEqual(object a, object b)
-	{
-		var aType = a.GetType();
-		var bType = b.GetType();
-		if (aType != bType)
-		{
-			throw new Exception("Type mismatch: {aType} != {bType}.");
-		}
-	}
-
 	private class PatternMismatchException : Exception
 	{
 		public readonly Token Start;
@@ -203,7 +193,6 @@ public class Interpreter : AST.IExprVisitor<Env, object>
 			{
 				throw new ArgumentException($"no such field: {name}");
 			}
-			checkTypesEqual(value, values.Peek());
 			return new Record { Fields = Fields.SetItem(name, values!.Pop().Push(value)) };
 		}
 
@@ -470,13 +459,7 @@ public class Interpreter : AST.IExprVisitor<Env, object>
 		List l = List.Empty;
 		foreach (var itemExpr in expr.Elements)
 		{
-			var item = evaluate(env, itemExpr);
-			if (!l.IsEmpty)
-			{
-				try { checkTypesEqual(l[0], item); }
-				catch { throw new RuntimeError(itemExpr.Start, "List items must all have same type."); }
-			}
-			l = l.Add(item);
+			l = l.Add(evaluate(env, itemExpr));
 		}
 		return l;
 	}