diff --git a/GNUmakefile.in b/GNUmakefile.in
index 2352fc1171..5f4c82ab8b 100644
--- a/GNUmakefile.in
+++ b/GNUmakefile.in
@@ -47,7 +47,7 @@ $(call recurse,distprep coverage,doc src config contrib)
 # it's not built by default
 $(call recurse,clean,doc contrib src config)
 clean:
-	rm -rf tmp_install/
+	rm -rf tmp_install/ portlock/
 # Garbage from autoconf:
 	@rm -rf autom4te.cache/
 
@@ -58,7 +58,7 @@ distclean maintainer-clean:
 	$(MAKE) -C contrib $@
 	$(MAKE) -C config $@
 	$(MAKE) -C src $@
-	rm -rf tmp_install/
+	rm -rf tmp_install/ portlock/
 # Garbage from autoconf:
 	@rm -rf autom4te.cache/
 	rm -f config.cache config.log config.status GNUmakefile