diff --git a/spike-wars/build.gradle b/spike-wars/build.gradle
index b20e28c..5fa031a 100644
--- a/spike-wars/build.gradle
+++ b/spike-wars/build.gradle
@@ -88,6 +88,7 @@ task minifyJavaScript(
     def argsArr = []
     argsArr << '--compilation_level=SIMPLE_OPTIMIZATIONS'
     argsArr << "--js_output_file=build/webroot/js/${project.name}-${project.version}.min.js"
+    argsArr << '--language-in=ECMASCRIPT5'
     argsArr << "build/webroot/js/${project.name}-${project.version}.js"
 
     args argsArr
diff --git a/spike-wars/src/main/js/spike-wars-artist.js b/spike-wars/src/main/js/spike-wars-artist.js
index 5d514c9..5687cdf 100644
--- a/spike-wars/src/main/js/spike-wars-artist.js
+++ b/spike-wars/src/main/js/spike-wars-artist.js
@@ -49,4 +49,8 @@ export default class SpikeWarsArtist {
       Math.floor(idx / this.cols) * this.tileHeight,
       this.tileWidth, this.tileHeight); }
  
+  drawImage(image: CanvasImageSource, row: number, col: number): void {
+    this.canvas2d.drawImage(image,
+      row * this.tileWidth, col * this.tileWidth,
+      this.tileWidth, this.tileHeight); }
 }