diff --git a/build-constraints.yaml b/build-constraints.yaml
index fb2d116b..007d7213 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1784,7 +1784,7 @@ packages:
         - fedora-dists
         - fedora-haskell-tools
         - HaXml
-        - hkgr
+        - hkgr < 0 # via simple-cabal
         - http-directory
         - http-query
         - hwk
@@ -1796,7 +1796,7 @@ packages:
         - rhbzquery
         - rpm-nvr
         - rpmbuild-order
-        - simple-cabal
+        - simple-cabal < 0 # https://github.com/juhp/simple-cabal/issues/1
         - simple-cmd
         - simple-cmd-args
         - stack-all