diff --git a/.docs/lib/HTMLPicture.js b/.docs/lib/HTMLPicture.js
index 3cf053a..654ced8 100644
--- a/.docs/lib/HTMLPicture.js
+++ b/.docs/lib/HTMLPicture.js
@@ -62,7 +62,8 @@ async function srcset(source_image, target_dir, urlpath, format = "__AUTO__", si
 	debug(`SOURCE_SIZE`, source_size, `TARGET_FORMAT`, target_format);
 	
 	let setitems = await Promise.all(sizes.map(async (size) => {
-		let target_filename = `${source_parsed.name}_${size}.${target_format}`;
+		let target_filename = `${source_parsed.name}_${size}.${target_format}`
+			.replace(/%/, "pcent");
 		let target_current = path.join(
 			target_dir,
 			target_filename