diff --git a/build-constraints.yaml b/build-constraints.yaml
index ba392743..d6012d8e 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -330,7 +330,7 @@ packages:
         - git-vogue < 0 # 0.3.0.2 compile fail
 
     "Manuel Bärenz <programming@manuelbaerenz.de> @turion":
-        - dunai
+        - dunai < 0 # https://github.com/commercialhaskell/stackage/issues/6751
         - essence-of-live-coding
         - essence-of-live-coding-gloss
         - essence-of-live-coding-pulse