diff --git a/js/render/draw_debug.js b/js/render/draw_debug.js
index 9544a8fe405..a86ad9c3b9e 100644
--- a/js/render/draw_debug.js
+++ b/js/render/draw_debug.js
@@ -5,20 +5,20 @@ var browser = require('../util/browser');
 
 module.exports = drawDebug;
 
-function drawDebug(painter, coords) {
+function drawDebug(painter, source, coords) {
     if (painter.isOpaquePass) return;
     if (!painter.options.debug) return;
 
     for (var i = 0; i < coords.length; i++) {
-        drawDebugTile(painter, coords[i]);
+        drawDebugTile(painter, source, coords[i]);
     }
 }
 
-function drawDebugTile(painter, coord) {
+function drawDebugTile(painter, source, coord) {
     var gl = painter.gl;
 
     var shader = painter.debugShader;
-    gl.switchShader(shader, painter.calculatePosMatrix(coord));
+    gl.switchShader(shader, painter.calculatePosMatrix(coord, source.maxzoom));
 
     // draw bounding rectangle
     gl.bindBuffer(gl.ARRAY_BUFFER, painter.debugBuffer);
diff --git a/js/render/painter.js b/js/render/painter.js
index 30059eb9964..fd2a8c4fa84 100644
--- a/js/render/painter.js
+++ b/js/render/painter.js
@@ -299,7 +299,9 @@ Painter.prototype.renderPass = function(options) {
             this.renderLayer(this, source, layer, coords);
         }
 
-        draw.debug(this, coords);
+        if (source) {
+            draw.debug(this, source, coords);
+        }
     }
 };
 
diff --git a/package.json b/package.json
index 9743e765183..996d9ffe556 100644
--- a/package.json
+++ b/package.json
@@ -38,7 +38,7 @@
     "eslint": "^1.5.0",
     "eslint-config-mourner": "^1.0.0",
     "istanbul": "^0.4.1",
-    "mapbox-gl-test-suite": "mapbox/mapbox-gl-test-suite#3fe57d5b2c885f758cc7667dbcce14a214b790e0",
+    "mapbox-gl-test-suite": "mapbox/mapbox-gl-test-suite#ff214a62ba73fd64defffc40bffa3a2dfb7b2b55",
     "prova": "^2.1.2",
     "sinon": "^1.15.4",
     "st": "^1.0.0",
diff --git a/test/render.test.js b/test/render.test.js
index b3bc14c8ddd..b6d2f2f9971 100644
--- a/test/render.test.js
+++ b/test/render.test.js
@@ -28,6 +28,9 @@ suite.run('js', {tests: tests}, function(style, options, callback) {
         attributionControl: false
     });
 
+    if (options.debug) map.debug = true;
+    if (options.collisionDebug) map.collisionDebug = true;
+
     var gl = map.painter.gl;
 
     map.once('load', function() {