diff --git a/src/Distribution/Nixpkgs/Haskell/FromStack.hs b/src/Distribution/Nixpkgs/Haskell/FromStack.hs
index e16859a..ad2857f 100644
--- a/src/Distribution/Nixpkgs/Haskell/FromStack.hs
+++ b/src/Distribution/Nixpkgs/Haskell/FromStack.hs
@@ -5,11 +5,12 @@ import Control.Lens
 import Data.Set.Lens
 import Distribution.Compiler (CompilerInfo(..))
 import Distribution.System (Platform(..))
-import Distribution.Package (PackageName, PackageIdentifier(..), Dependency(..))
+import Distribution.Package (PackageName, PackageIdentifier(..), Dependency(..), packageId)
 import Distribution.PackageDescription
 import Distribution.Nixpkgs.Haskell.FromStack.Package
 import Distribution.Nixpkgs.Haskell.PackageSourceSpec
 import Distribution.Nixpkgs.Haskell.FromCabal
+import Distribution.Nixpkgs.Haskell.FromCabal.Flags (configureCabalFlags)
 import Distribution.Nixpkgs.Haskell.Derivation
 import Stackage.BuildPlan
 import Stackage.Types (CabalFileInfo(..),PackageConstraints(..), DepInfo(..), SimpleDesc(..), TestState(..))
@@ -63,19 +64,20 @@ fromPackage conf pconf plan pkg =
     configureBenches
       | pcBenches constraints == Don'tBuild = removeBenches
       | otherwise = id
-    flags = Map.toList (pcFlagOverrides constraints)
+    defaultFlags = configureCabalFlags (packageId (pkgCabal pkg))
+    flags = defaultFlags <> mkFlagAssignment (Map.toList $ pcFlagOverrides constraints)
     (descr, missingDeps) = finalizeGenericPackageDescription
       (haskellResolver conf)
       (targetPlatform conf)
       (targetCompiler conf)
-      (mkFlagAssignment flags)
+      flags
       (planDependencies plan)
       (configureBenches . configureTests $ pkgCabal pkg)
     genericDrv = fromPackageDescription
       (haskellResolver conf)
       (nixpkgsResolver conf)
       missingDeps
-      (mkFlagAssignment flags)
+      flags
       descr
     depName (Dependency name _) = name
     testDeps = setOf
diff --git a/src/Distribution/Nixpkgs/Haskell/Stack.hs b/src/Distribution/Nixpkgs/Haskell/Stack.hs
index 1585d7b..82dca0f 100644
--- a/src/Distribution/Nixpkgs/Haskell/Stack.hs
+++ b/src/Distribution/Nixpkgs/Haskell/Stack.hs
@@ -32,6 +32,7 @@ makeLenses ''StackPackagesConfig
 getStackPackageFromDb :: DB.HackageDB -> StackPackage -> IO Package
 getStackPackageFromDb hackageDb stackPackage = do
   PackageSourceSpec.getPackage'
+    False
     False
     (pure hackageDb)
     (stackLocationToSource (stackPackage ^. spLocation) (stackPackage ^. spDir))
diff --git a/src/LtsHaskell.hs b/src/LtsHaskell.hs
index 21f2676..84d4431 100644
--- a/src/LtsHaskell.hs
+++ b/src/LtsHaskell.hs
@@ -46,7 +46,7 @@ getPackageFromRepo allCabalHashesPath mSha1Hash pkgId = do
     tarballSHA256 = fromMaybe
       (error (display pkgId ++ ": meta data has no SHA256 hash for the tarball"))
       (view (mHashes . at "SHA256") meta)
-    source = DerivationSource "url" ("mirror://hackage/" ++ display pkgId ++ ".tar.gz") "" tarballSHA256
+    source = DerivationSource "url" ("mirror://hackage/" ++ display pkgId ++ ".tar.gz") "" tarballSHA256 Nothing
   return $ Package source False pkgDesc
 
 getPackageFromDb :: DB.HackageDB -> PackageIdentifier -> IO Package
diff --git a/stack.yaml b/stack.yaml
index 4ba6f65..08b88a0 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,6 +1,9 @@
-resolver: lts-12.2
+resolver: lts-12.16
 extra-deps:
-  - yaml-0.8.31.1
+  - cabal2nix-2.13
+  - hpack-0.31.1
+  - infer-license-0.2.0
+  - yaml-0.10.0
   - git: https://github.com/fpco/stackage-curator.git
     commit: 73c5ed06602990c33d3fec1711e27875f283b6bf
   - git: https://github.com/jwiegley/gitlib.git
@@ -9,3 +12,6 @@ extra-deps:
       - gitlib
       - gitlib-libgit2
 
+nix:
+  enable: false  # run stack with --nix to enable
+  packages: [ icu, openssl, zlib ]
diff --git a/stackage2nix.cabal b/stackage2nix.cabal
index ad6aa37..0d1d2f4 100644
--- a/stackage2nix.cabal
+++ b/stackage2nix.cabal
@@ -35,7 +35,7 @@ library
                      , QuickCheck
                      , aeson
                      , bytestring
-                     , cabal2nix >= 2.7.2
+                     , cabal2nix >= 2.11
                      , containers
                      , deepseq
                      , distribution-nixpkgs >= 1.1