diff --git a/ocaml/Makefile.am b/ocaml/Makefile.am
index c781b7e9a..d5eb878f1 100644
--- a/ocaml/Makefile.am
+++ b/ocaml/Makefile.am
@@ -141,7 +141,7 @@ guestfs.cmx: guestfs.ml
 
 depend: .depend
 
-.depend: $(wildcard $(abs_srcdir)/*.mli) $(wildcard $(abs_srcdir)/*.ml)
+.depend: $(wildcard $(abs_srcdir)/*.mli) $(wildcard $(abs_srcdir)/*.ml) $(wildcard $(abs_srcdir)/t/*.ml)
 	rm -f $@ $@-t
 	$(OCAMLFIND) ocamldep -I ../ocaml -I $(abs_srcdir) $^ | \
 	  $(SED) 's/ *$$//' | \