diff --git a/build-constraints.yaml b/build-constraints.yaml
index a0947af3..5bfac0bb 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -740,6 +740,7 @@ packages:
     "Leon Mergen leon@solatis.com @solatis":
         - bitcoin-script
         - bitcoin-tx
+        - hexstring
         - network-attoparsec
         - network-anonymous-i2p