diff --git a/Makefile b/Makefile
index 6c72ead1ef..f23955f5f4 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,8 @@ pypi-files: AUTHORS Changelog.md LICENSE README.md README.txt supportedsites \
         tar pypi-files lazy-extractors install uninstall
 
 clean-test:
-	rm -rf test/testdata/sigs/player-*.js tmp/ *.annotations.xml *.aria2 *.description *.dump *.frag \
+	rm -rf test/testdata/sigs/player-*.js test/testdata/thumbnails/*.webp "test/testdata/thumbnails/foo %d bar/foo"* \
+	tmp/ *.annotations.xml *.aria2 *.description *.dump *.frag \
 	*.frag.aria2 *.frag.urls *.info.json *.live_chat.json *.meta *.part* *.tmp *.temp *.unknown_video *.ytdl \
 	*.3gp *.ape *.ass *.avi *.desktop *.f4v *.flac *.flv *.gif *.jpeg *.jpg *.lrc *.m4a *.m4v *.mhtml *.mkv *.mov *.mp3 *.mp4 \
 	*.mpg *.mpga *.oga *.ogg *.opus *.png *.sbv *.srt *.ssa *.swf *.tt *.ttml *.url *.vtt *.wav *.webloc *.webm *.webp