diff --git a/tests/mgcp/Makefile.am b/tests/mgcp/Makefile.am
index 73ad1cf..78d9f6a 100644
--- a/tests/mgcp/Makefile.am
+++ b/tests/mgcp/Makefile.am
@@ -45,3 +45,6 @@
 	$(LIBOSMONETIF_LIBS) \
 	-lm  \
 	$(NULL)
+
+update_exp:
+	$(builddir)/mgcp_test >$(srcdir)/mgcp_test.ok