diff --git a/build-constraints.yaml b/build-constraints.yaml
index 9757c739..2d43a760 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -257,6 +257,7 @@ packages:
 
     "Tom McLaughlin <tom@codedown.io> @thomasjm":
         - aeson-typescript < 0 # th-abstraction-0.3
+        - slack-progressbar
 
     "Paulo Tanaka <paulot@fb.com> @paulot":
         # on behalf of Bryan O'Sullivan @bos: