diff --git a/src/os/flatpak.zig b/src/os/flatpak.zig
--- a/src/os/flatpak.zig
+++ b/src/os/flatpak.zig
@@ -41,7 +41,7 @@
         clear_env: bool = false,
         /// Kill the sandbox when the caller disappears from the session bus
         watch_bus: bool = false,
-        _reserved: u30 = 0,
+        _reserved: std.meta.Int(.unsigned, @bitSizeOf(c_uint) - 2) = 0,
     };
 
     /// Argv are the arguments to call on the host with argv[0] being