diff --git a/src/layer/tile/GridLayer.js b/src/layer/tile/GridLayer.js
index 471db8b2..4b4457f5 100644
--- a/src/layer/tile/GridLayer.js
+++ b/src/layer/tile/GridLayer.js
@@ -314,8 +314,8 @@ L.GridLayer = L.Class.extend({
 		    nwPoint = coords.multiplyBy(tileSize),
 		    sePoint = nwPoint.add([tileSize, tileSize]),
 
-		    nw = this._map.unproject(nwPoint),
-		    se = this._map.unproject(sePoint);
+		    nw = this._map.unproject(nwPoint, coords.z),
+		    se = this._map.unproject(sePoint, coords.z);
 
 		return new L.LatLngBounds(nw, se);
 	},
diff --git a/src/layer/tile/TileLayer.WMS.js b/src/layer/tile/TileLayer.WMS.js
index 7c895088..54200e11 100644
--- a/src/layer/tile/TileLayer.WMS.js
+++ b/src/layer/tile/TileLayer.WMS.js
@@ -1,5 +1,5 @@
 /*
- * L.TileLayer.WMS is used for putting WMS tile layers on the map.
+ * L.TileLayer.WMS is used for WMS tile layers.
  */
 
 L.TileLayer.WMS = L.TileLayer.extend({
@@ -14,29 +14,25 @@ L.TileLayer.WMS = L.TileLayer.extend({
 		transparent: false
 	},
 
-	initialize: function (url, options) { // (String, Object)
+	initialize: function (url, options) {
 
 		this._url = url;
 
-		var wmsParams = L.extend({}, this.defaultWmsParams),
-		    tileSize = options.tileSize || this.options.tileSize;
-
-		if (options.detectRetina && L.Browser.retina) {
-			wmsParams.width = wmsParams.height = tileSize * 2;
-		} else {
-			wmsParams.width = wmsParams.height = tileSize;
-		}
+		var wmsParams = L.extend({}, this.defaultWmsParams);
 
+		// all keys that are not TileLayer options go to WMS params
 		for (var i in options) {
-			// all keys that are not TileLayer options go to WMS params
 			if (!this.options.hasOwnProperty(i) && i !== 'crs') {
 				wmsParams[i] = options[i];
 			}
 		}
 
-		this.wmsParams = wmsParams;
+		options = L.setOptions(this, options);
 
-		L.setOptions(this, options);
+		wmsParams.width = wmsParams.height =
+				options.tileSize * (options.detectRetina && L.Browser.retina ? 2 : 1);
+
+		this.wmsParams = wmsParams;
 	},
 
 	onAdd: function (map) {
@@ -51,21 +47,17 @@ L.TileLayer.WMS = L.TileLayer.extend({
 		L.TileLayer.prototype.onAdd.call(this, map);
 	},
 
-	getTileUrl: function (tilePoint) { // (Point, Number) -> String
+	getTileUrl: function (coords) {
 
-		var map = this._map,
-		    tileSize = this.options.tileSize,
+		var tileBounds = this._tileCoordsToBounds(coords),
+		    nw = this._crs.project(tileBounds.getNorthWest()),
+		    se = this._crs.project(tileBounds.getSouthEast()),
 
-		    nwPoint = tilePoint.multiplyBy(tileSize),
-		    sePoint = nwPoint.add([tileSize, tileSize]),
+		    bbox = (this._wmsVersion >= 1.3 && this._crs === L.CRS.EPSG4326 ?
+			[se.y, nw.x, nw.y, se.x] :
+			[nw.x, se.y, se.x, nw.y]).join(','),
 
-		    nw = this._crs.project(map.unproject(nwPoint, tilePoint.z)),
-		    se = this._crs.project(map.unproject(sePoint, tilePoint.z)),
-		    bbox = this._wmsVersion >= 1.3 && this._crs === L.CRS.EPSG4326 ?
-		        [se.y, nw.x, nw.y, se.x].join(',') :
-		        [nw.x, se.y, se.x, nw.y].join(','),
-
-		    url = L.Util.template(this._url, {s: this._getSubdomain(tilePoint)});
+		    url = L.Util.template(this._url, {s: this._getSubdomain(coords)});
 
 		return url + L.Util.getParamString(this.wmsParams, url, true) + '&BBOX=' + bbox;
 	},