diff --git a/gpu/src/adapter.zig b/gpu/src/adapter.zig
index 968f2398..a7e8f489 100644
--- a/gpu/src/adapter.zig
+++ b/gpu/src/adapter.zig
@@ -45,7 +45,7 @@ pub const Adapter = *opaque {
 pub const RequestDeviceCallback = fn (
     status: RequestDeviceStatus,
     device: Device,
-    message: [*:0]const u8,
+    message: ?[*:0]const u8,
     userdata: *anyopaque,
 ) callconv(.C) void;