diff --git a/build-constraints.yaml b/build-constraints.yaml
index a62140ec..d7cfd79e 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2436,6 +2436,9 @@ expected-test-failures:
     # https://github.com/snoyberg/classy-prelude/issues/117
     - classy-prelude
 
+    # https://github.com/massysett/rainbox/issues/2
+    - rainbox
+
 # end of expected-test-failures