diff --git a/src/drawer.js b/src/drawer.js
index 0165d1f3..34cf3506 100644
--- a/src/drawer.js
+++ b/src/drawer.js
@@ -403,6 +403,16 @@ function updateViewport( drawer ) {
         viewportTL = rotatedBounds.getTopLeft();
         viewportBR = rotatedBounds.getBottomRight();
     }
+    else if (degrees !== 0) {
+        // This is just an approximation.
+        var orthBounds = viewportBounds.rotate(90);
+        viewportBounds.x -= orthBounds.width / 2;
+        viewportBounds.y -= orthBounds.height / 2;
+        viewportBounds.width += orthBounds.width;
+        viewportBounds.height += orthBounds.height;
+        viewportTL = viewportBounds.getTopLeft();
+        viewportBR = viewportBounds.getBottomRight();
+    }
 
     //Don't draw if completely outside of the viewport
     if  ( !drawer.wrapHorizontal &&
diff --git a/src/navigator.js b/src/navigator.js
index d07a2bba..9e18d6ca 100644
--- a/src/navigator.js
+++ b/src/navigator.js
@@ -241,7 +241,7 @@ $.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /*
                     (this.container.clientHeight === 0 ? 1 : this.container.clientHeight)
                 );
             if ( !containerSize.equals( this.oldContainerSize ) ) {
-                var oldBounds = this.viewport.getBounds().rotate(this.viewport.degrees);
+                var oldBounds = this.viewport.getBounds();
                 var oldCenter = this.viewport.getCenter();
                 this.viewport.resize( containerSize, true );
                 var imageHeight = 1 / this.source.aspectRatio;
diff --git a/src/rectangle.js b/src/rectangle.js
index 99172e7d..4e3746eb 100644
--- a/src/rectangle.js
+++ b/src/rectangle.js
@@ -194,7 +194,7 @@ $.Rect.prototype = /** @lends OpenSeadragon.Rect.prototype */{
             newTopLeft;
 
         degrees = ( degrees + 360 ) % 360;
-        if( degrees % 90 !== 0 ) {
+        if (degrees % 90 !== 0) {
             throw new Error('Currently only 0, 90, 180, and 270 degrees are supported.');
         }
 
diff --git a/src/viewport.js b/src/viewport.js
index e1231500..4de54f96 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -713,10 +713,7 @@ $.Viewport.prototype = /** @lends OpenSeadragon.Viewport.prototype */{
     },
 
     /**
-     * Currently only 90 degree rotation is supported and it only works
-     * with the canvas. Additionally, the navigator does not rotate yet,
-     * debug mode doesn't rotate yet, and overlay rotation is only
-     * partially supported.
+     * Rotates this viewport to the angle specified.
      * @function
      * @return {OpenSeadragon.Viewport} Chainable.
      */
@@ -726,9 +723,6 @@ $.Viewport.prototype = /** @lends OpenSeadragon.Viewport.prototype */{
         }
 
         degrees = ( degrees + 360 ) % 360;
-        if( degrees % 90 !== 0 ) {
-            throw new Error('Currently only 0, 90, 180, and 270 degrees are supported.');
-        }
         this.degrees = degrees;
         this.viewer.forceRedraw();