diff --git a/build-constraints.yaml b/build-constraints.yaml
index 81716dcb..6210ebcc 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -549,7 +549,7 @@ packages:
         - circle-packing
         - arbtt
         # GHC 8 - ghc-heap-view
-        # GHC 8 - tttool
+        - tttool
         # GHC 8 - gipeda
         - list-fusion-probe
         - haskell-spacegoo