diff --git a/src/unix2db.zig b/src/unix2db.zig
index 7a64f6b..e1b5111 100644
--- a/src/unix2db.zig
+++ b/src/unix2db.zig
@@ -101,7 +101,7 @@ fn execute(
         return fail(errc.wrap("construct DB from corpus"), stderr, err);
     defer db.deinit(allocator);
 
-    const fd = os.open(out_fname, os.O.WRONLY | os.O.TRUNC | os.O.CREAT, 0644) catch |err|
+    const fd = os.open(out_fname, os.O.WRONLY | os.O.TRUNC | os.O.CREAT, 0o644) catch |err|
         return fail(errc.wrapf("open for writing {s}", .{out_fname}), stderr, err);
     errdefer os.close(fd);