diff --git a/src/linearizer.c b/src/linearizer.c
index a982979..57b360a 100644
--- a/src/linearizer.c
+++ b/src/linearizer.c
@@ -74,6 +74,11 @@ static void linearize_function(LinearizerState *linearizer);
 static Instruction *allocate_instruction(Proc *proc, enum opcode op, unsigned line_number);
 static void free_temp_pseudo(Proc *proc, Pseudo *pseudo, bool free_local);
 
+static AstNode* astlist_get(AstNodeList *list, unsigned int i)
+{
+	return (AstNode*) raviX_ptrlist_nth_entry((struct PtrList *) list, i);
+}
+
 /**
  * Allocates a register by reusing a free'd register if possible otherwise
  * allocating a new one
@@ -1537,9 +1542,14 @@ static void linearize_local_statement(Proc *proc, AstNode *stmt)
 
 static Pseudo *linearize_builtin_expression(Proc *proc, AstNode *expr)
 {
+	// For now the only built-in is C__new
+	if (expr->builtin_expr.token != TOK_C__new) {
+		handle_error(proc->linearizer->compiler_state, "feature not yet implemented");
+	}
 	Instruction *insn = allocate_instruction(proc, op_C__new, expr->line_number);
-	add_instruction_operand(proc, insn, allocate_constant_pseudo(proc, allocate_string_constant(proc, expr->builtin_expr.type_name)));
-	Pseudo *size_expr = linearize_expression(proc, expr->builtin_expr.size_expr);
+	const StringObject *type_name = astlist_get(expr->builtin_expr.arg_list, 0)->literal_expr.u.ts;
+	add_instruction_operand(proc, insn, allocate_constant_pseudo(proc, allocate_string_constant(proc, type_name)));
+	Pseudo *size_expr = linearize_expression(proc, astlist_get(expr->builtin_expr.arg_list, 1));
 	add_instruction_operand(proc, insn, size_expr);
 	Pseudo *target = allocate_temp_pseudo(proc, RAVI_TUSERDATA);
 	add_instruction_target(proc, insn, target);
diff --git a/src/parser.c b/src/parser.c
index 7c07309..b8b43c4 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -869,29 +869,39 @@ static AstNode *parse_primary_expression(ParserState *parser)
 	return primary_expr;
 }
 
-/* Parse C__new '(' string ',' expr ')' */
-static AstNode *parse_builtin_expression(ParserState *parser)
+/* Parse builtins:
+ * C__new '(' string ',' expr ')'
+ */
+static AstNode *parse_builtin_expression(ParserState *parser, int token)
 {
 	LexerState *ls = parser->ls;
 
+	if (token != TOK_C__new) {
+		raviX_syntaxerror(ls, "Unsupported builtin: expecting C__new");
+	}
+
 	AstNode *builtin_expr = allocate_expr_ast_node(parser, EXPR_BUILTIN);
 	builtin_expr->builtin_expr.type.type_code = RAVI_TUSERDATA;
 	builtin_expr->builtin_expr.type.type_name = NULL;
-	builtin_expr->builtin_expr.type_name = NULL;
-	builtin_expr->builtin_expr.size_expr = NULL;
+	builtin_expr->builtin_expr.token = token;
+	builtin_expr->builtin_expr.arg_list = NULL;
 
 	raviX_next(ls);
 	checknext(ls, '(');
-	check(ls, TOK_STRING);
-	builtin_expr->builtin_expr.type_name = ls->t.seminfo.ts;
-	raviX_next(ls);
+	AstNode *expr1 = parse_expression(parser);
+	if (expr1->type != EXPR_LITERAL && expr1->literal_expr.type.type_code != RAVI_TSTRING) {
+		raviX_syntaxerror(ls, "Expected a size expression as second argument to C__new");
+	}
 	checknext(ls, ',');
-	builtin_expr->builtin_expr.size_expr = parse_expression(parser);
-	if (builtin_expr->builtin_expr.size_expr == NULL) {
+	AstNode *expr2 = parse_expression(parser);
+	if (expr2 == NULL) {
 		raviX_syntaxerror(ls, "Expected a size expression as second argument to C__new");
 	}
 	checknext(ls, ')');
 
+	add_ast_node(parser->compiler_state, &builtin_expr->builtin_expr.arg_list, expr1);
+	add_ast_node(parser->compiler_state, &builtin_expr->builtin_expr.arg_list, expr2);
+
 	return builtin_expr;
 }
 
@@ -903,7 +913,7 @@ static AstNode *parse_suffixed_expression(ParserState *parser)
 	primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
 	int line = ls->linenumber;
 	if (ls->t.token == TOK_C__new) {
-		return parse_builtin_expression(parser);
+		return parse_builtin_expression(parser, TOK_C__new);
 	}
 	AstNode *suffixed_expr = allocate_expr_ast_node(parser, EXPR_SUFFIXED);
 	suffixed_expr->suffixed_expr.primary_expr = parse_primary_expression(parser);
diff --git a/src/parser.h b/src/parser.h
index a49901d..a5d6a1c 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -372,8 +372,8 @@ struct FunctionCallExpression {
 struct BuiltinExpression {
 	/* Currently only for C__new but potentially could be other builtins */
 	BASE_EXPRESSION_FIELDS;
-	const StringObject *type_name; /* Name of the C struct type */
-	AstNode *size_expr; /* Number of elements of type - > 1 means array */
+	int token;
+	AstNodeList *arg_list;
 };
 #undef BASE_EXPRESSION_FIELDS