diff --git a/stack.yaml b/stack.yaml
index f1b8d73c23..e6da9d6237 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -7,6 +7,7 @@ packages:
 extra-deps:
 - ansi-terminal-0.10.2
 - base-compat-0.11.0
+- brittany-0.12.1.1@rev:2
 - butcher-1.3.3.1
 - Cabal-3.0.2.0
 - cabal-helper-1.1.0.0