diff --git a/src/shared.js b/src/shared.js
index 5175848..786f3ac 100644
--- a/src/shared.js
+++ b/src/shared.js
@@ -1,5 +1,12 @@
 function getFilenameFromUrl(url) {
-	return decodeURIComponent(url.split('/').slice(-1)[0]);
+	let filename = url.split('/').slice(-1)[0];
+	try {
+		filename = decodeURIComponent(filename)
+	} catch (ex) {
+		// filename could not be decoded because of improper encoding with %
+		// leave filename as-is and continue
+	}
+	return filename;
 }
 
 exports.getFilenameFromUrl = getFilenameFromUrl;