diff --git a/src/background.rs b/src/background.rs
index 2987eeb..f8bacb5 100644
--- a/src/background.rs
+++ b/src/background.rs
@@ -7,6 +7,8 @@ pub struct Background {
     pub tiles: Vec<Vec<u16>>,
     /// Camera scroll (negative draw offset) for rendering
     pub scroll: IVec2,
+    /// Size (used for rendering)
+    pub size: IVec2,
     /// Are tiles indices half-tile indices?
     pub half_tile: bool,
     /// Is this background being displayed?
@@ -22,6 +24,7 @@ impl Default for Background {
             scroll: IVec2::ZERO,
             half_tile: false,
             active: true,
+            size: IVec2 { x: 19, y: 11 },
         }
     }
 }
diff --git a/src/gsa_render_to_screen.rs b/src/gsa_render_to_screen.rs
index 36601f7..c550225 100644
--- a/src/gsa_render_to_screen.rs
+++ b/src/gsa_render_to_screen.rs
@@ -41,10 +41,14 @@ fn render_map(target: &mut [u8], map: &Background, tileset: &[u8], screen_size:
     } as i32;
     let mut startx = map.scroll.x / tilesize;
     let mut starty = map.scroll.y / tilesize;
-    let endx =
-        (BACKGROUND_MAX_SIZE as i32).min(startx + (screen_size.x / TILE_SIZE as i32 + 1) * tcmult);
-    let endy =
-        (BACKGROUND_MAX_SIZE as i32).min(starty + (screen_size.y / TILE_SIZE as i32 + 1) * tcmult);
+    let endx = map
+        .size
+        .x
+        .min(startx + (screen_size.x / TILE_SIZE as i32 + 1) * tcmult);
+    let endy = map
+        .size
+        .y
+        .min(starty + (screen_size.y / TILE_SIZE as i32 + 1) * tcmult);
     startx = 0.max(startx);
     starty = 0.max(starty);
     for x in startx..endx {