diff --git a/src/tilesource.js b/src/tilesource.js
index fa51915b..48d5bf10 100644
--- a/src/tilesource.js
+++ b/src/tilesource.js
@@ -191,11 +191,26 @@ $.TileSource = function( width, height, tileSize, tileOverlap, minLevel, maxLeve
             (  options.width / options.height ) : 1;
         this.dimensions  = new $.Point( options.width, options.height );
         
-        if ( options.tileSize ){
-            this._tileWidth = this._tileHeight = options.tileSize;
+        if ( this.tileSize ){
+            this._tileWidth = this._tileHeight = this.tileSize;
+            delete this.tileSize;
         } else {
-            this._tileWidth = options.tileWidth ? options.tileWidth : 0;
-            this._tileHeight = options.tileHeight ? options.tileHeight: 0;
+            if( this.tileWidth ){
+                // We were passed tileWidth in options, but we want to rename it
+                // with a leading underscore to make clear that it is not safe to directly modify it
+                this._tileWidth = this.tileWidth;
+                delete this.tileWidth;
+            } else {
+                this._tileWidth = 0;
+            }
+
+            if( this.tileHeight ){
+                // See note above about renaming this.tileWidth
+                this._tileHeight = this.tileHeight;
+                delete this.tileHeight;
+            } else {
+                this._tileHeight = 0;
+            }
         }
         
         this.tileOverlap = options.tileOverlap ? options.tileOverlap : 0;
@@ -230,7 +245,7 @@ $.TileSource.prototype = /** @lends OpenSeadragon.TileSource.prototype */{
      * Return the tileWidth for a given level.
      * Subclasses should override this if tileWidth can be different at different levels
      *   such as in IIIFTileSource.  Code should use this function rather than reading
-     *   from .tileWidth directly.
+     *   from ._tileWidth directly.
      * @function
      * @param {Number} level
      */
@@ -245,7 +260,7 @@ $.TileSource.prototype = /** @lends OpenSeadragon.TileSource.prototype */{
      * Return the tileHeight for a given level.
      * Subclasses should override this if tileHeight can be different at different levels
      *   such as in IIIFTileSource.  Code should use this function rather than reading
-     *   from .tileHeight directly.
+     *   from ._tileHeight directly.
      * @function
      * @param {Number} level
      */
diff --git a/test/modules/tilesource.js b/test/modules/tilesource.js
new file mode 100644
index 00000000..59d8b77f
--- /dev/null
+++ b/test/modules/tilesource.js
@@ -0,0 +1,51 @@
+/* global module, ok, equal, start, test, testLog, Util */
+(function() {
+    
+    module('TileSource', {
+        setup: function() {
+            testLog.reset();
+        }
+    });
+    
+    
+    test("should set sane tile size defaults", function() {
+        var source = new OpenSeadragon.TileSource();
+        
+        equal(source.getTileWidth(), 0, "getTileWidth() should return 0 if not provided a size");
+        equal(source.getTileHeight(), 0, "getTileHeight() should return 0 if not provided a size");
+    });
+    
+    test("providing tileSize", function(){
+        var tileSize = 256,
+            source = new OpenSeadragon.TileSource({
+                tileSize: tileSize
+            });
+        
+        equal(source.tileSize, undefined, "tileSize should not be set on the tileSource");
+        equal(source.getTileWidth(), tileSize, "getTileWidth() should equal tileSize");
+        equal(source.getTileHeight(), tileSize, "getTileHeight() should equal tileSize");
+    });
+    
+    
+    test("providing tileWidth and tileHeight", function(){
+        var tileWidth = 256,
+            tileHeight = 512,
+            source = new OpenSeadragon.TileSource({
+                tileWidth: tileWidth,
+                tileHeight: tileHeight
+            });
+        
+        equal(source._tileWidth, tileWidth, "tileWidth option should set _tileWidth");
+        equal(source._tileHeight, tileHeight, "tileHeight option should set _tileHeight");
+        equal(source.tileWidth, undefined, "tileWidth should be renamed _tileWidth");
+        equal(source.tileHeight, undefined, "tileHeight should be renamed _tileHeight");
+        equal(source.getTileWidth(), tileWidth, "getTileWidth() should equal tileWidth");
+        equal(source.getTileHeight(), tileHeight, "getTileHeight() should equal tileHeight");
+    });
+    
+    test('getTileSize() deprecation', function() {
+        var source = new OpenSeadragon.TileSource();
+        Util.testDeprecation(source, 'getTileSize');
+    });
+
+}());
diff --git a/test/test.html b/test/test.html
index ae4863e8..e52eb66a 100644
--- a/test/test.html
+++ b/test/test.html
@@ -36,6 +36,7 @@
     <script src="/test/modules/tiledimage.js"></script>
     <script src="/test/modules/tilecache.js"></script>
     <script src="/test/modules/referencestrip.js"></script>
+    <script src="/test/modules/tilesource.js"></script>
     <script src="/test/modules/tilesourcecollection.js"></script>
     <script src="/test/modules/spring.js"></script>
     <!-- The navigator tests are the slowest (for now; hopefully they can be sped up)