diff --git a/libsecret/tests/Makefile.am b/libsecret/tests/Makefile.am
index a0f88a2..92c528d 100644
--- a/libsecret/tests/Makefile.am
+++ b/libsecret/tests/Makefile.am
@@ -89,7 +89,7 @@ VALA_FLAGS = \
 VALA_TESTS_VAPIS = \
 	$(builddir)/../libsecret-unstable.vapi \
 	$(builddir)/../libsecret-@SECRET_MAJOR@.vapi \
-	mock-service-0.vapi
+	$(builddir)/mock-service-0.vapi
 
 VALA_SRCS = $(VALA_TESTS:=.vala)