diff --git a/cabal.project b/cabal.project
index 81dda4f..cddb885 100755
--- a/cabal.project
+++ b/cabal.project
@@ -2,6 +2,7 @@ import: ./project-stackage/lts-21.25.config
 
 packages:
     .
+  , updo
 
 constraints:
     crypton ==1.0.0
diff --git a/stack.yaml b/stack.yaml
index 3d63d1c..672d2c9 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,10 +2,15 @@ user-message: "WARNING: This stack project is generated."
 
 resolver: lts-21.25
 
+# We have 2 packages.
 packages:
   - ./.
+  - ./updo
 
 extra-deps:
+  # Package versions for published packages either not on Stackage or
+  # not matching the version on Stackage for the resolver we use.
+  # These package-version extra dependencies are equivalent to cabal constraints.
   - crypton-1.0.0
   - crypton-connection-0.4.0
   - crypton-x509-1.7.6