diff --git a/data/update_imagery.js b/data/update_imagery.js
index 761b93fa3..225f9c153 100644
--- a/data/update_imagery.js
+++ b/data/update_imagery.js
@@ -54,7 +54,7 @@ sources.concat(whitelist).forEach(function(source) {
     var supportedProjection = source.available_projections &&
         supportedWMSProjections.find(function(supportedProjection) {
             return source.available_projections.some(function(projection) {
-              return supportedProjection === projection;
+                return supportedProjection === projection;
             })
         });
     if (source.type === 'wms' && supportedProjection === undefined) return;
@@ -67,7 +67,7 @@ sources.concat(whitelist).forEach(function(source) {
     };
 
     if (source.type === 'wms') {
-      im.projection = supportedProjection;
+        im.projection = supportedProjection;
     }
 
     var startDate, endDate, isValid;
diff --git a/modules/renderer/background_source.js b/modules/renderer/background_source.js
index df5de7df1..74d75cd3a 100644
--- a/modules/renderer/background_source.js
+++ b/modules/renderer/background_source.js
@@ -33,9 +33,15 @@ function vintageRange(vintage) {
 }
 
 function getEPSG3857XY(x, y, z) {
+    //polyfill for IE11, PhantomJS
+    var sinh = Math.sinh || function(x) {
+        var y = Math.exp(x);
+        return (y - 1 / y) / 2;
+    };
+
     var zoomSize = Math.pow(2, z);
     var lon = x / zoomSize * Math.PI * 2 - Math.PI;
-    var lat = Math.atan(Math.sinh(Math.PI * (1 - 2 * y / zoomSize)));
+    var lat = Math.atan(sinh(Math.PI * (1 - 2 * y / zoomSize)));
     var mercCoords = d3_geoMercatorRaw(lon, lat);
     return {
         x: 20037508.34 / Math.PI * mercCoords[0],
diff --git a/test/spec/renderer/background_source.js b/test/spec/renderer/background_source.js
index 21f64ad92..2828bdf0c 100644
--- a/test/spec/renderer/background_source.js
+++ b/test/spec/renderer/background_source.js
@@ -1,48 +1,71 @@
-describe('iD.BackgroundSource', function() {
+describe('iD.rendererBackgroundSource', function() {
     it('does not error with blank template', function() {
-        var source = iD.BackgroundSource({ template: '' });
+        var source = iD.rendererBackgroundSource({ template: '' });
         expect(source.url([0,1,2])).to.equal('');
     });
 
-    it('generates a tile-generating source', function() {
-        var source = iD.BackgroundSource({ template: '{z}/{x}/{y}' });
+    it('supports tms replacement tokens', function() {
+        var source = iD.rendererBackgroundSource({
+            type: 'tms',
+            template: '{z}/{x}/{y}'
+        });
         expect(source.url([0,1,2])).to.equal('2/0/1');
     });
 
+    it('supports wms replacement tokens', function() {
+        var source = iD.rendererBackgroundSource({
+            type: 'wms',
+            projection: 'EPSG:3857',
+            template: 'SRS={proj}&FORMAT=image/jpeg&WIDTH={width}&HEIGHT={height}&BBOX={bbox}'
+        });
+
+        var result = iD.utilStringQs(source.url([0,1,2]));
+        expect(result.SRS).to.equal('EPSG:3857');
+        expect(result.FORMAT).to.equal('image/jpeg');
+        expect(result.WIDTH).to.equal('256');
+        expect(result.HEIGHT).to.equal('256');
+
+        var bbox = result.BBOX.split(',');
+        expect(+bbox[0]).to.be.closeTo(-20037508.34, 1e-3);
+        expect(+bbox[1]).to.be.closeTo(0, 1e-3);
+        expect(+bbox[2]).to.be.closeTo(-10018754.17, 1e-3);
+        expect(+bbox[3]).to.be.closeTo(10018754.17, 1e-3);
+    });
+
     it('supports subdomains', function() {
-        var source = iD.BackgroundSource({ template: '{switch:a,b}/{z}/{x}/{y}'});
+        var source = iD.rendererBackgroundSource({ template: '{switch:a,b}/{z}/{x}/{y}'});
         expect(source.url([0,1,2])).to.equal('b/2/0/1');
     });
 
     it('distributes requests between subdomains', function() {
-        var source = iD.BackgroundSource({ template: '{switch:a,b}/{z}/{x}/{y}' });
+        var source = iD.rendererBackgroundSource({ template: '{switch:a,b}/{z}/{x}/{y}' });
         expect(source.url([0,1,1])).to.equal('b/1/0/1');
         expect(source.url([0,2,1])).to.equal('a/1/0/2');
     });
 
     it('correctly displays an overlay with no overzoom specified', function() {
-        var source = iD.BackgroundSource({ scaleExtent: [6,16] });
+        var source = iD.rendererBackgroundSource({ scaleExtent: [6,16] });
         expect(source.validZoom(10)).to.be.true;
         expect(source.validZoom(3)).to.be.false;
         expect(source.validZoom(17)).to.be.true;
     });
 
     it('correctly displays an overlay with an invalid overzoom', function() {
-        var source = iD.BackgroundSource({ scaleExtent: [6,16], overzoom: 'gibberish'});
+        var source = iD.rendererBackgroundSource({ scaleExtent: [6,16], overzoom: 'gibberish'});
         expect(source.validZoom(10)).to.be.true;
         expect(source.validZoom(3)).to.be.false;
         expect(source.validZoom(17)).to.be.true;
     });
 
     it('correctly displays an overlay with overzoom:true', function() {
-        var source = iD.BackgroundSource({ scaleExtent: [6,16], overzoom: true});
+        var source = iD.rendererBackgroundSource({ scaleExtent: [6,16], overzoom: true});
         expect(source.validZoom(10)).to.be.true;
         expect(source.validZoom(3)).to.be.false;
         expect(source.validZoom(17)).to.be.true;
     });
 
     it('correctly displays an overlay with overzoom:false', function() {
-        var source = iD.BackgroundSource({ scaleExtent: [6,16], overzoom: false});
+        var source = iD.rendererBackgroundSource({ scaleExtent: [6,16], overzoom: false});
         expect(source.validZoom(10)).to.be.true;
         expect(source.validZoom(3)).to.be.false;
         expect(source.validZoom(17)).to.be.false;