diff --git a/build-constraints.yaml b/build-constraints.yaml
index bc7e845f..cc9df68e 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3150,7 +3150,7 @@ packages:
         - pathwalk
 
     "John Galt <jgalt@centromere.net> @centromere":
-        - cacophony
+        - cacophony < 0 # 0.11.0 https://github.com/haskell-cryptography/cacophony/issues/19
         - blake2
         - nfc