Flagging the missing API entries.
diff --git a/grpc.def b/grpc.def
index d37e687..bd0bc85 100644
--- a/grpc.def
+++ b/grpc.def
@@ -99,6 +99,7 @@
     grpc_auth_context_set_peer_identity_property_name
     grpc_channel_credentials_release
     grpc_google_default_credentials_create
+    grpc_set_ssl_roots_override_callback
     grpc_ssl_credentials_create
     grpc_call_credentials_release
     grpc_composite_channel_credentials_create