diff --git a/build-constraints.yaml b/build-constraints.yaml
index 8ba049f4..da403686 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -6731,6 +6731,9 @@ packages:
       - nettle < 0
       - protocol-radius-test < 0
       - relational-schemas < 0
+      # Blocked by packages in the above set
+      - cipher-rc4 < 0
+      - cprng-aes < 0
 
 
     "Stackage upper bounds":