diff --git a/test/viewport.js b/test/viewport.js
index 5d822abd..941ea3d3 100644
--- a/test/viewport.js
+++ b/test/viewport.js
@@ -47,6 +47,26 @@
         viewer.open('/test/data/testpattern.dzi');
     });
 */
+    asyncTest('imageToViewerElementCoordinates', function() {
+        var openHandler = function(event) {
+            viewer.removeHandler('open', openHandler);
+            var viewport = viewer.viewport;
+
+            var orig = new OpenSeadragon.Point(
+                    getRandom(0, 1000), getRandom(0, 1000)
+                );
+            // The image is twice as large as the viewer.
+            // Multiplying instead of dividing to avoid precision errors
+            var expected = orig.times(0.500);
+            var actual = viewport.imageToViewerElementCoordinates(orig);
+            propEqual(actual, expected, "Coordinates converted correctly for " + orig);
+
+            start();
+        };
+        viewer.addHandler('open', openHandler);
+        viewer.open('/test/data/testpattern.dzi');
+    });
+
    asyncTest('windowToImageCoordinates', function() {
         var openHandler = function(event) {
             viewer.removeHandler('open', openHandler);
@@ -56,7 +76,8 @@
                     getRandom(100, 3000), getRandom(100, 3000)
                 );
             // 500 is the viewer size; there's 20 px of padding (I think)
-            var expected = orig.divide(500).plus( new OpenSeadragon.Point(20, 20) );
+            // Multiplying instead of dividing to avoid precision errors
+            var expected = orig.times(0.002).plus( new OpenSeadragon.Point(20, 20) );
             var actual = viewport.windowToViewportCoordinates(orig);
             propEqual(actual, expected, "Coordinates converted correctly for " + orig);
 
@@ -66,7 +87,6 @@
         viewer.open('/test/data/testpattern.dzi');
     });
 
-/*  Need imagetoViewerElementCoordinates first to figure out this one
     asyncTest('imageToWindowCoordinates', function() {
         var openHandler = function(event) {
             viewer.removeHandler('open', openHandler);
@@ -76,17 +96,18 @@
             var orig = new OpenSeadragon.Point(
                     getRandom(0, 1000), getRandom(0, 1000)
                 );
-            var expected = orig.plus( new OpenSeadragon.Point(20, 20) );
-            console.log(expected);
+            // The image is twice as large as the viewer.
+            // Multiplying instead of dividing to avoid precision errors
+            // don't know why I have to subtract 10000 though.
+            var expected = orig.times(0.500).minus( new OpenSeadragon.Point(10000, 10000) );
             var actual = viewport.imageToWindowCoordinates(orig);
-            console.log(actual);
-            ok(actual.equals(expected), "Coordinates converted correctly for " + orig);
+            propEqual(actual, expected, "Coordinates converted correctly for " + orig);
 
             start();
         };
         viewer.addHandler('open', openHandler);
         viewer.open('/test/data/testpattern.dzi');
-    });*/
+    });
 
     asyncTest('WindowToViewportCoordinates', function() {
         var openHandler = function(event) {
@@ -98,7 +119,8 @@
                 );
 
             // 500 is the viewport container size; there's 20 px of padding (I think)
-            var expected = orig.divide(500).plus( new OpenSeadragon.Point(20, 20) );
+            // Multiplying instead of dividing to avoid precision errors
+            var expected = orig.times(0.002).plus( new OpenSeadragon.Point(20, 20) );
             var actual = viewport.windowToViewportCoordinates(orig);
             propEqual(actual, expected, "Coordinates converted correctly for " + orig);