diff --git a/make/subdirs.mk b/make/subdirs.mk
index b6900949..5f111955 100644
--- a/make/subdirs.mk
+++ b/make/subdirs.mk
@@ -10,6 +10,7 @@ install.dirs:
 	set -e; for dir in $(SUBDIRS); do make -C $$dir install; done
 clean.dirs:
 	set -e; for dir in $(SUBDIRS); do make -C $$dir clean; done
+	rm -f *.done
 distclean.dirs:
 	set -e; for dir in $(SUBDIRS); do make -C $$dir distclean; done