diff --git a/src/overlay.js b/src/overlay.js
index d104e8cd..7465d573 100644
--- a/src/overlay.js
+++ b/src/overlay.js
@@ -417,7 +417,7 @@
          * @returns {OpenSeadragon.Rect} overlay bounds
          */
         getBounds: function(viewport) {
-            $.console.assert(!viewport, 'Calling Overlay.getBounds withouth ' +
+            $.console.assert(viewport, 'Calling Overlay.getBounds withouth ' +
                 'specifying a viewport is deprecated.');
             var width = this.width;
             var height = this.height;
@@ -442,11 +442,22 @@
                 this.rotationMode === $.OverlayRotationMode.EXACT) {
                 return bounds;
             }
-            // If overlay not fully scalable, BOUNDING_BOX falls back to EXACT
-            if (this.rotationMode === $.OverlayRotationMode.BOUNDING_BOX &&
-                (this.width === null || this.height === null)) {
-                return bounds;
+            if (this.rotationMode === $.OverlayRotationMode.BOUNDING_BOX) {
+                // If overlay not fully scalable, BOUNDING_BOX falls back to EXACT
+                if (this.width === null || this.height === null) {
+                    return bounds;
+                }
+                // It is easier to just compute the position and size and
+                // convert to viewport coordinates.
+                var positionAndSize = this._getOverlayPositionAndSize(viewport);
+                return viewport.viewerElementToViewportRectangle(new $.Rect(
+                    positionAndSize.position.x,
+                    positionAndSize.position.y,
+                    positionAndSize.size.x,
+                    positionAndSize.size.y));
             }
+
+            // NO_ROTATION case
             return bounds.rotate(-viewport.degrees,
                 this._getPlacementPoint(bounds));
         }
diff --git a/src/viewport.js b/src/viewport.js
index 821d8075..13841da7 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -1262,6 +1262,20 @@ $.Viewport.prototype = {
         return this.pixelFromPoint( point, true );
     },
 
+    /**
+     * Convert a rectangle in pixel coordinates relative to the viewer element
+     * to viewport coordinates.
+     * @param {OpenSeadragon.Rect} rectangle the rectangle to convert
+     * @returns {OpenSeadragon.Rect} the converted rectangle
+     */
+    viewerElementToViewportRectangle: function(rectangle) {
+        return $.Rect.fromSummits(
+            this.pointFromPixel(rectangle.getTopLeft(), true),
+            this.pointFromPixel(rectangle.getTopRight(), true),
+            this.pointFromPixel(rectangle.getBottomLeft(), true)
+        );
+    },
+
     /**
      * Convert a rectangle in viewport coordinates to pixel coordinates relative
      * to the viewer element.
diff --git a/test/modules/overlays.js b/test/modules/overlays.js
index 0183d61f..49eb0c4f 100644
--- a/test/modules/overlays.js
+++ b/test/modules/overlays.js
@@ -982,4 +982,63 @@
             start();
         });
     });
+
+    // ----------
+    asyncTest('Fully scaled overlay rotation mode BOUNDING_BOX', function() {
+        viewer = OpenSeadragon({
+            id: 'example-overlays',
+            prefixUrl: '/build/openseadragon/images/',
+            tileSources: '/test/data/testpattern.dzi',
+            springStiffness: 100, // Faster animation = faster tests
+            degrees: 45,
+            overlays: [{
+                    id: "fully-scaled-overlay",
+                    x: 1,
+                    y: 1,
+                    width: 1,
+                    height: 1,
+                    placement: OpenSeadragon.Placement.BOTTOM_RIGHT,
+                    rotationMode: OpenSeadragon.OverlayRotationMode.BOUNDING_BOX
+                }]
+        });
+
+        viewer.addOnceHandler('open', function() {
+            var viewport = viewer.viewport;
+
+            var $overlay = $("#fully-scaled-overlay");
+            var expectedRect = viewport.viewportToViewerElementRectangle(
+                new OpenSeadragon.Rect(0, 0, 1, 1)).getBoundingBox();
+            var actualPosition = $overlay.position();
+            Util.assessNumericValue(actualPosition.left, expectedRect.x, epsilon,
+                "Scaled overlay position.x should adjust to rotation.");
+            Util.assessNumericValue(actualPosition.top, expectedRect.y, epsilon,
+                "Scaled overlay position.y should adjust to rotation.");
+
+            var actualWidth = $overlay.width();
+            var actualHeight = $overlay.height();
+            Util.assessNumericValue(actualWidth, expectedRect.width, epsilon,
+                "Scaled overlay width should not adjust to rotation.");
+            Util.assessNumericValue(actualHeight, expectedRect.height, epsilon,
+                "Scaled overlay height should not adjust to rotation.");
+
+            var actualBounds = viewer.getOverlayById("fully-scaled-overlay")
+                .getBounds(viewport);
+            var expectedBounds = new OpenSeadragon.Rect(
+                    0.5, -0.5, Math.sqrt(2), Math.sqrt(2), 45);
+            var boundsEpsilon = 0.000001;
+            Util.assessNumericValue(actualBounds.x, expectedBounds.x, boundsEpsilon,
+                "The fully scaled overlay should have adjusted bounds.x");
+            Util.assessNumericValue(actualBounds.y, expectedBounds.y, boundsEpsilon,
+                "The fully scaled overlay should have adjusted bounds.y");
+            Util.assessNumericValue(actualBounds.width, expectedBounds.width, boundsEpsilon,
+                "The fully scaled overlay should have adjusted bounds.width");
+            Util.assessNumericValue(actualBounds.height, expectedBounds.height, boundsEpsilon,
+                "The fully scaled overlay should have adjusted bounds.height");
+            Util.assessNumericValue(actualBounds.degrees, expectedBounds.degrees, boundsEpsilon,
+                "The fully scaled overlay should have adjusted bounds.degrees");
+
+            start();
+        });
+    });
+
 })();