diff --git a/build-constraints.yaml b/build-constraints.yaml
index 3a16b784..6ed34b0f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3617,7 +3617,7 @@ packages:
         - merkle-tree
         - oblivious-transfer
         - pairing
-        - libraft
+        - libraft < 0 # No instance for ‘ConvertText ByteString [Char]’
         - galois-field
 
     "Daishi Nakajima <nakaji.dayo@gmail.com> @nakaji-dayo":