Fix windows build
diff --git a/binding.gyp b/binding.gyp
index 9dcd2e3..5d707cd 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -761,6 +761,7 @@
'src/core/ext/lb_policy/pick_first/pick_first.c',
'src/core/ext/lb_policy/round_robin/round_robin.c',
'src/core/ext/resolver/dns/c_ares/dns_resolver_ares.c',
+ 'src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_fallback.c',
'src/core/ext/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c',
'src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper.c',
'src/core/ext/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c',