diff --git a/ly-ui/build.zig b/ly-ui/build.zig
index 4e14ec6..20a46ae 100644
--- a/ly-ui/build.zig
+++ b/ly-ui/build.zig
@@ -25,7 +25,7 @@ pub fn build(b: *std.Build) void {
     translate_c.defineCMacroRaw("TB_IMPL");
     // TODO 0.16.0: Workaround until Aro gets better...
     // https://codeberg.org/ziglang/translate-c/issues/319
-    translate_c.defineCMacroRaw("_GNU_SOURCE");
+    translate_c.defineCMacro("_XOPEN_SOURCE", "700");
     translate_c.defineCMacro("TB_OPT_ATTR_W", "32"); // Enable 24-bit color support + styling (32-bit)
     const termbox2 = translate_c.addModule("termbox2");
     mod.addImport("termbox2", termbox2);