diff --git a/src/reskit/level/system.rs b/src/reskit/level/system.rs
index cbf25be..fed6f94 100644
--- a/src/reskit/level/system.rs
+++ b/src/reskit/level/system.rs
@@ -285,9 +285,12 @@ pub fn get_sprites( tilemap: &TiledTilemap, sprite_ids: &HashMap<String, u16> )
         let sprite_id = sprite_ids.get( &sprite_metadata.id ).ok_or( format!( "invalid file: undefined sprite id \"{}\"", sprite_metadata.id ) )?;
         result.extend( sprite_id.to_be_bytes() );
 
+        let tiles_across = sprite.image.width() / 8;
+        let frames: u16 = ( tiles_across / ( sprite_metadata.width as u32 ) ) as u16;
+
         let tile_index_location = tiles_before + tiles_after;
         result.extend( ( tile_index_location as u16 ).to_be_bytes() );
-        tiles_after += ( sprite_metadata.width * sprite_metadata.height ) as u32;
+        tiles_after += ( ( sprite_metadata.width as u16 * sprite_metadata.height as u16 ) * frames ) as u32;
 
         result.push( sprite_metadata.width );
 
@@ -297,8 +300,6 @@ pub fn get_sprites( tilemap: &TiledTilemap, sprite_ids: &HashMap<String, u16> )
 
         // One animation per .tsx file
         // Animations run like a filmstrip across, never down
-        let tiles_across = sprite.image.width() / 8;
-        let frames: u16 = ( tiles_across / ( sprite_metadata.width as u32 ) ) as u16;
         result.extend( frames.to_be_bytes() );
 
         if let Some( jiffies ) = sprite_metadata.anim_interval {