diff --git a/src/07-03.zig b/src/07-03.zig
index cf43f27..e29c343 100644
--- a/src/07-03.zig
+++ b/src/07-03.zig
@@ -2,9 +2,9 @@ const std = @import("std");
 const print = std.debug.print;
 
 pub fn main() !void {
-    var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
-    defer arena.deinit();
-    const allocator = arena.allocator();
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer if (gpa.deinit() != .ok) @panic("leak");
+    const allocator = gpa.allocator();
 
     var pool: std.Thread.Pool = undefined;
     try pool.init(.{