use call

lib/single-file/modules/css-fonts-alt-minifier.js

@@ -224,7 +224,7 @@ this.singlefile.lib.modules.fontsAltMinifier = this.singlefile.lib.modules.fonts
 						await Promise.race(
 							[
 								fontFace.load().then(() => fontFace.loaded).then(() => source.valid = true),
-								new Promise(resolve => setTimeout(() => { source.valid = true; resolve(); }, FONT_MAX_LOAD_DELAY))
+								new Promise(resolve => setTimeout.call(window, () => { source.valid = true; resolve(); }, FONT_MAX_LOAD_DELAY))
 							]);
 					} catch (error) {
 						// ignored