diff --git a/build-constraints.yaml b/build-constraints.yaml
index 3b8cfb0e..ff681820 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1,4 +1,6 @@
 ghc-major-version: "8.6"
+# new curator is supposed to use exact GHC version
+ghc-version: "8.6.3"
 
 # This affects which version of the Cabal file format we allow. We
 # should ensure that this is always no greater than the version