diff --git a/Makefile b/Makefile
index 8d615e4b2c9081e20b16fb3931cea5ef951c540c..331cb03f841de9ffc5711e876acd402e4816fb87 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ all: Makefile.coq
 
 clean: Makefile.coq
 	+@make -f Makefile.coq clean
-	find theories tests \( -name "*.d" -o -name "*.vo" -o -name "*.aux" -o -name "*.cache" -o -name "*.glob" -o -name "*.vio" \) -print -delete || true
+	find theories tests exercises solutions \( -name "*.d" -o -name "*.vo" -o -name "*.vo[sk]" -o -name "*.aux" -o -name "*.cache" -o -name "*.glob" -o -name "*.vio" \) -print -delete || true
 	rm -f Makefile.coq .lia.cache
 .PHONY: clean