diff --git a/src/components/colorbar/constants.js b/src/components/colorbar/constants.js
new file mode 100644
index 00000000000..0fad225f102
--- /dev/null
+++ b/src/components/colorbar/constants.js
@@ -0,0 +1,26 @@
+/**
+* Copyright 2012-2017, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+'use strict';
+
+module.exports = {
+    cn: {
+        colorbar: 'colorbar',
+        cbbg: 'cbbg',
+        cbfill: 'cbfill',
+        cbfills: 'cbfills',
+        cbline: 'cbline',
+        cblines: 'cblines',
+        cbaxis: 'cbaxis',
+        cbtitleunshift: 'cbtitleunshift',
+        cbtitle: 'cbtitle',
+        cboutline: 'cboutline',
+        crisp: 'crisp',
+        jsPlaceholder: 'js-placeholder'
+    }
+};
diff --git a/src/components/colorbar/draw.js b/src/components/colorbar/draw.js
index d41334c8d32..d584c134fa8 100644
--- a/src/components/colorbar/draw.js
+++ b/src/components/colorbar/draw.js
@@ -31,7 +31,7 @@ var handleAxisPositionDefaults = require('../../plots/cartesian/position_default
 var axisLayoutAttrs = require('../../plots/cartesian/layout_attributes');
 
 var attributes = require('./attributes');
-
+var cn = require('./constants').cn;
 
 module.exports = function draw(gd, id) {
     // opts: options object, containing everything from attributes
@@ -248,15 +248,16 @@ module.exports = function draw(gd, id) {
         // now draw the elements
         var container = fullLayout._infolayer.selectAll('g.' + id).data([0]);
         container.enter().append('g').classed(id, true)
+            .classed(cn.colorbar, true)
             .each(function() {
                 var s = d3.select(this);
-                s.append('rect').classed('cbbg', true);
-                s.append('g').classed('cbfills', true);
-                s.append('g').classed('cblines', true);
-                s.append('g').classed('cbaxis', true).classed('crisp', true);
-                s.append('g').classed('cbtitleunshift', true)
-                    .append('g').classed('cbtitle', true);
-                s.append('rect').classed('cboutline', true);
+                s.append('rect').classed(cn.cbbg, true);
+                s.append('g').classed(cn.cbfills, true);
+                s.append('g').classed(cn.cblines, true);
+                s.append('g').classed(cn.cbaxis, true).classed(cn.crisp, true);
+                s.append('g').classed(cn.cbtitleunshift, true)
+                    .append('g').classed(cn.cbtitle, true);
+                s.append('rect').classed(cn.cboutline, true);
                 s.select('.cbtitle').datum(0);
             });
         container.attr('transform', 'translate(' + Math.round(gs.l) +
@@ -315,7 +316,7 @@ module.exports = function draw(gd, id) {
                     }
                 }
                 else if(titleText.node() &&
-                        !titleText.classed('js-placeholder')) {
+                        !titleText.classed(cn.jsPlaceholder)) {
                     titleHeight = Drawing.bBox(titleText.node()).height;
                 }
                 if(titleHeight) {
@@ -348,7 +349,7 @@ module.exports = function draw(gd, id) {
                 .selectAll('rect.cbfill')
                     .data(filllevels);
             fills.enter().append('rect')
-                .classed('cbfill', true)
+                .classed(cn.cbfill, true)
                 .style('stroke', 'none');
             fills.exit().remove();
             fills.each(function(d, i) {
@@ -389,7 +390,7 @@ module.exports = function draw(gd, id) {
                     .data(opts.line.color && opts.line.width ?
                         linelevels : []);
             lines.enter().append('path')
-                .classed('cbline', true);
+                .classed(cn.cbline, true);
             lines.exit().remove();
             lines.each(function(d) {
                 d3.select(this)
@@ -479,7 +480,7 @@ module.exports = function draw(gd, id) {
             var innerWidth = thickPx + opts.outlinewidth / 2 +
                     Drawing.bBox(cbAxisOut._axislayer.node()).width;
             titleEl = titleCont.select('text');
-            if(titleEl.node() && !titleEl.classed('js-placeholder')) {
+            if(titleEl.node() && !titleEl.classed(cn.jsPlaceholder)) {
                 var mathJaxNode = titleCont
                         .select('.h' + cbAxisOut._id + 'title-math-group')
                         .node(),
diff --git a/src/traces/choropleth/attributes.js b/src/traces/choropleth/attributes.js
index cab58297206..6c9ffb93cbf 100644
--- a/src/traces/choropleth/attributes.js
+++ b/src/traces/choropleth/attributes.js
@@ -48,7 +48,7 @@ module.exports = extendFlat({
     hoverinfo: extendFlat({}, plotAttrs.hoverinfo, {
         editType: 'calc',
         flags: ['location', 'z', 'text', 'name']
-    }),
+    })
 },
     extendDeepAll({}, colorscaleAttrs, {
         zmax: {editType: 'calc'},