diff --git a/build-constraints.yaml b/build-constraints.yaml
index 6cdc625c..68fa71e7 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -419,7 +419,7 @@ packages:
         - sandwich-quickcheck
         - sandwich-slack
         - sandwich-webdriver
-        - slack-progressbar
+        - slack-progressbar < 0 # https://github.com/codedownio/slack-progressbar/issues/1
         - webdriver
 
     "Paulo Tanaka <paulot@fb.com> @paulot":