diff --git a/crop_rot/src/model.rs b/crop_rot/src/model.rs
index 3961ce0..6975940 100644
--- a/crop_rot/src/model.rs
+++ b/crop_rot/src/model.rs
@@ -117,7 +117,11 @@ impl<T> Harvest<T> where
     T: Harvestable + Debug + Clone + Display
 {
     pub fn new(color_weights: &ColorWeights, config: &Config) -> Harvest<T> {
-        let rolled_fields: usize = rand::distributions::Uniform::new(3, 6).sample(&mut thread_rng()) * 2;
+        let rolled_fields: usize = (
+            3 + 
+            rand::thread_rng().gen_range(0..=1) + 
+            rand::thread_rng().gen_range(0..=1)
+        ) * 2;
 
         let mut fields: Vec<T> = Vec::new();
 
diff --git a/flake.nix b/flake.nix
index 11a3b21..239f24c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,6 +26,9 @@
           else rust.stable.latest.default;
       })
     ];
+
+    python-packages = ps: with ps; [numpy];
+
     supportedSystems = ["x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin"];
     forEachSupportedSystem = f:
       nixpkgs.lib.genAttrs supportedSystems (system:
@@ -36,6 +39,8 @@
     devShells = forEachSupportedSystem ({pkgs}: {
       default = pkgs.mkShell {
         packages = with pkgs; [
+          (python3.withPackages python-packages)
+
           rustToolchain
           openssl
           pkg-config