diff --git a/changelog.txt b/changelog.txt
index 9824e9e9..d16a6d4e 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -54,6 +54,7 @@ OPENSEADRAGON CHANGELOG
     * Viewer.innerTracker.dragHandler: preventDefaultAction == true prevents viewer panning with mouse/touch
     * Viewer.innerTracker.scrollHandler: preventDefaultAction == true prevents viewer zooming on mousewheel/pinch
 * Fixed: IE8 error with custom buttons - "Object doesn't support this action" (#279)
+* Support IIIF servers that don't report tile dimensions (#286)
 
 0.9.131:
 
diff --git a/package.json b/package.json
index 73c90e02..63c432b9 100644
--- a/package.json
+++ b/package.json
@@ -3,17 +3,17 @@
   "version": "0.9.131",
   "description": "Provides a smooth, zoomable user interface for HTML/Javascript.",
   "devDependencies": {
-    "grunt": "~0.4.0",
-    "grunt-contrib-compress": "~0.5.0",
-    "grunt-contrib-concat": "~0.1.2",
-    "grunt-contrib-jshint": "~0.6.0",
-    "grunt-contrib-uglify": "~0.2.2",
-    "grunt-contrib-qunit": "~0.2.0",
-    "grunt-contrib-connect": "~0.1.2",
-    "grunt-contrib-watch": "~0.2.0",
-    "grunt-contrib-clean": "~0.4.0",
+    "grunt": "~0.4.1",
+    "grunt-contrib-compress": "~0.5.2",
+    "grunt-contrib-concat": "~0.3.0",
+    "grunt-contrib-jshint": "~0.7.2",
+    "grunt-contrib-uglify": "~0.2.7",
+    "grunt-contrib-qunit": "~0.3.0",
+    "grunt-contrib-connect": "~0.5.0",
+    "grunt-contrib-watch": "~0.5.3",
+    "grunt-contrib-clean": "~0.5.0",
     "grunt-git-describe": "~2.0.0",
-    "grunt-text-replace": "~0.3.2"
+    "grunt-text-replace": "~0.3.9"
   },
   "scripts": {
     "test": "grunt test"
diff --git a/src/iiif1_1tilesource.js b/src/iiif1_1tilesource.js
index 2f90355c..319aa0b1 100644
--- a/src/iiif1_1tilesource.js
+++ b/src/iiif1_1tilesource.js
@@ -51,7 +51,12 @@ $.IIIF1_1TileSource = function( options ){
         throw new Error('IIIF required parameters not provided.');
     }
 
-    options.tileSize = this.tile_width;
+    if ( !(this.tile_width && this.tile_height) ) {
+        // use the short dimension if there aren't tile sizes provided.
+        options.tileSize = Math.min(this.height, this.width);
+    } else {
+        options.tileSize = this.tile_width;
+    }
 
     if (! options.maxLevel ) {
         var mf = -1;
@@ -82,7 +87,6 @@ $.extend( $.IIIF1_1TileSource.prototype, $.TileSource.prototype, /** @lends Open
             "http://library.stanford.edu/iiif/image-api/1.1/compliance.html#level0" == data.profile ||
             "http://library.stanford.edu/iiif/image-api/1.1/compliance.html#level1" == data.profile ||
             "http://library.stanford.edu/iiif/image-api/1.1/compliance.html#level2" == data.profile ||
-            "http://library.stanford.edu/iiif/image-api/1.1/compliance.html#level3" == data.profile ||
             "http://library.stanford.edu/iiif/image-api/1.1/compliance.html" == data.profile
         );
     },
diff --git a/test/data/iiif_no_tiles.json b/test/data/iiif_no_tiles.json
new file mode 100644
index 00000000..7f677b32
--- /dev/null
+++ b/test/data/iiif_no_tiles.json
@@ -0,0 +1,19 @@
+{
+  "profile": "http://library.stanford.edu/iiif/image-api/1.1/compliance.html#level2",
+  "height": 850,
+  "width": 1024,
+  "qualities": [
+    "native",
+    "color",
+    "grey",
+    "bitonal"
+  ],
+  "formats": [
+    "jpg",
+    "png",
+    "gif"
+  ],
+  "@context": "http://library.stanford.edu/iiif/image-api/1.1/context.json",
+  "@id": "http://localhost:8000/test/data/iiif_no_tiles"
+}
+
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/128,107/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/128,107/0/native.jpg
new file mode 100644
index 00000000..e0bacd02
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/128,107/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/16,14/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/16,14/0/native.jpg
new file mode 100644
index 00000000..4cee30fa
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/16,14/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/256,213/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/256,213/0/native.jpg
new file mode 100644
index 00000000..6c8c5441
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/256,213/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/32,27/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/32,27/0/native.jpg
new file mode 100644
index 00000000..f97752d8
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/32,27/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/512,425/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/512,425/0/native.jpg
new file mode 100644
index 00000000..c3300449
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/512,425/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/64,54/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/64,54/0/native.jpg
new file mode 100644
index 00000000..ad7f30c8
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/64,54/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/0,0,1024,850/8,7/0/native.jpg b/test/data/iiif_no_tiles/0,0,1024,850/8,7/0/native.jpg
new file mode 100644
index 00000000..893409b0
Binary files /dev/null and b/test/data/iiif_no_tiles/0,0,1024,850/8,7/0/native.jpg differ
diff --git a/test/data/iiif_no_tiles/full/full/0/native.jpg b/test/data/iiif_no_tiles/full/full/0/native.jpg
new file mode 100644
index 00000000..dcc1d22b
Binary files /dev/null and b/test/data/iiif_no_tiles/full/full/0/native.jpg differ
diff --git a/test/formats.js b/test/formats.js
index e0915a5c..9cabf816 100644
--- a/test/formats.js
+++ b/test/formats.js
@@ -80,4 +80,9 @@
         testOpen('iiif1_1.json');
     });
 
+        // ----------
+    asyncTest('IIIF No Tiles', function() {
+        testOpen('iiif_no_tiles.json');
+    });
+
 })();