diff --git a/crates/border-wars/src/map/generation.rs b/crates/border-wars/src/map/generation.rs
index 9efd643..2d320ca 100644
--- a/crates/border-wars/src/map/generation.rs
+++ b/crates/border-wars/src/map/generation.rs
@@ -28,7 +28,7 @@ pub struct StartMapGeneration {
     pub seed: u32,
 
     /// The radius of the map.
-    pub radius: usize,
+    pub radius: u16,
 }
 
 /// An event send when the map is generated.
@@ -41,12 +41,12 @@ fn generate_map(
     mut end_map_event: EventWriter<EndMapGeneration>,
     mut commands: Commands,
     mut noise: Local<Option<Perlin>>,
-    mut map_iterator: Local<Option<HexSpiral<isize>>>,
+    mut map_iterator: Local<Option<HexSpiral<i32>>>,
 ) {
     // Handle map generation events.
     for event in event.read() {
         *noise = Some(Perlin::new(event.seed));
-        *map_iterator = Some(HexPosition(0, 0).spiral(event.radius));
+        *map_iterator = Some(HexPosition(0, 0).spiral(event.radius as usize));
     }
 
     if let (Some(perlin), Some(spiral)) = (noise.as_ref(), map_iterator.as_mut()) {