diff --git a/build-constraints.yaml b/build-constraints.yaml
index 7e2b50c1..d59b23c0 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3559,6 +3559,7 @@ expected-test-failures:
     - redis-io
     - rethinkdb
     - rethinkdb-client-driver
+    - riak # needs riak server on localhost:8098
     - serialport # "The tests need two serial ports as command line arguments" https://github.com/jputcu/serialport/issues/30
     - serversession-backend-redis # redis
     - shake # Needs ghc on $PATH with some installed haskell packages