diff --git a/default.nix b/default.nix
index a80fab4..a0883a3 100644
--- a/default.nix
+++ b/default.nix
@@ -1,6 +1,7 @@
-{ mkDerivation, base, monad-loops, MonadRandom, pipes, protolude
-, QuickCheck, quickcheck-instances, random, random-fu
-, random-shuffle, stdenv, text
+{ mkDerivation, base, Cabal, cabal-test-quickcheck, extra
+, monad-loops, MonadRandom, pipes, protolude, QuickCheck
+, quickcheck-instances, random, random-fu, random-shuffle, stdenv
+, text
 }:
 mkDerivation {
   pname = "ga";
@@ -9,12 +10,17 @@ mkDerivation {
   isLibrary = true;
   isExecutable = true;
   libraryHaskellDepends = [
-    base monad-loops MonadRandom pipes protolude QuickCheck
+    base extra monad-loops MonadRandom pipes protolude QuickCheck
     quickcheck-instances random random-fu random-shuffle text
   ];
   executableHaskellDepends = [
-    base monad-loops MonadRandom pipes protolude QuickCheck
+    base extra monad-loops MonadRandom pipes protolude QuickCheck
     quickcheck-instances random random-fu random-shuffle text
   ];
+  testHaskellDepends = [
+    base Cabal cabal-test-quickcheck extra monad-loops MonadRandom
+    pipes protolude QuickCheck quickcheck-instances random random-fu
+    random-shuffle text
+  ];
   license = stdenv.lib.licenses.gpl3;
 }
diff --git a/ga.cabal b/ga.cabal
index 9ef3b08..c8f4452 100644
--- a/ga.cabal
+++ b/ga.cabal
@@ -15,15 +15,16 @@ build-type:          Simple
 
 library
   build-depends:       base ^>=4.12.0.0
+                     , extra
                      , MonadRandom
                      , monad-loops
-                     , random
-                     , random-fu
-                     , random-shuffle
                      , pipes
                      , protolude
                      , QuickCheck
                      , quickcheck-instances
+                     , random
+                     , random-fu
+                     , random-shuffle
                      , text
   default-language:    Haskell2010
   hs-source-dirs:      src
@@ -33,14 +34,28 @@ library
                      , SS19
                      , WS19
 
-
 executable ga
   build-depends:       base ^>=4.12.0.0
+                     , extra
                      , MonadRandom
                      , monad-loops
+                     , pipes
+                     , protolude
+                     , QuickCheck
+                     , quickcheck-instances
                      , random
                      , random-fu
                      , random-shuffle
+                     , text
+  default-language:    Haskell2010
+  hs-source-dirs:      src
+  main-is:             Main.hs
+  other-modules:       GA
+                     , Seminar
+                     , Pretty
+                     , SS19
+                     , WS19
+
                      , pipes
                      , protolude
                      , QuickCheck