added CLEANFILES to make distcheck run fine
diff --git a/tests/Makefile.am b/tests/Makefile.am
index d6bfc83..ad87116 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -6,6 +6,8 @@
 
 PERLFLAGS = -I$(srcdir)
 
+CLEANFILES = .http.pid .https.pid .ftp.pid .ftps.pid
+
 curl:
 	@cd $(top_builddir) && $(MAKE)