diff --git a/src/kernel/io/Testfile b/src/kernel/io/Testfile
index fa8cbd74c..6838e9e48 100644
--- a/src/kernel/io/Testfile
+++ b/src/kernel/io/Testfile
@@ -43,6 +43,7 @@ csf:
 # oops,there is a problem here, can't do this
 #	csf rsf.out - MyF convert=f2d | tsf - maxprec=t
 	$(EXEC) tsf csf.out				; nemo.coverage tsf.c
+	$(EXEC) csf rsf.out . help=m
 
 bsf:
 	@echo Running bsf