diff --git a/src/components/colorbar/draw.js b/src/components/colorbar/draw.js
index d817dd84635..9aa7f5be855 100644
--- a/src/components/colorbar/draw.js
+++ b/src/components/colorbar/draw.js
@@ -65,20 +65,23 @@ module.exports = function draw(gd, id) {
             return;
         }
         var zrange = d3.extent(((typeof opts.fillcolor === 'function') ?
-                opts.fillcolor : opts.line.color).domain()),
-            linelevels = [],
-            filllevels = [],
-            l,
-            linecolormap = typeof opts.line.color === 'function' ?
-                opts.line.color : function() { return opts.line.color; },
-            fillcolormap = typeof opts.fillcolor === 'function' ?
-                opts.fillcolor : function() { return opts.fillcolor; };
+            opts.fillcolor : opts.line.color).domain());
+        var linelevels = [];
+        var filllevels = [];
+        var linecolormap = typeof opts.line.color === 'function' ?
+            opts.line.color : function() { return opts.line.color; };
+        var fillcolormap = typeof opts.fillcolor === 'function' ?
+            opts.fillcolor : function() { return opts.fillcolor; };
+        var l;
+        var i;
 
         var l0 = opts.levels.end + opts.levels.size / 100,
             ls = opts.levels.size,
             zr0 = (1.001 * zrange[0] - 0.001 * zrange[1]),
             zr1 = (1.001 * zrange[1] - 0.001 * zrange[0]);
-        for(l = opts.levels.start; (l - l0) * ls < 0; l += ls) {
+        for(i = 0; i < 1e5; i++) {
+            l = opts.levels.start + i * ls;
+            if(ls > 0 ? (l >= l0) : (l <= l0)) break;
             if(l > zr0 && l < zr1) linelevels.push(l);
         }
 
@@ -86,7 +89,9 @@ module.exports = function draw(gd, id) {
             if(opts.filllevels) {
                 l0 = opts.filllevels.end + opts.filllevels.size / 100;
                 ls = opts.filllevels.size;
-                for(l = opts.filllevels.start; (l - l0) * ls < 0; l += ls) {
+                for(i = 0; i < 1e5; i++) {
+                    l = opts.filllevels.start + i * ls;
+                    if(ls > 0 ? (l >= l0) : (l <= l0)) break;
                     if(l > zrange[0] && l < zrange[1]) filllevels.push(l);
                 }
             }
diff --git a/test/image/baselines/21.png b/test/image/baselines/21.png
index 098370c0c47..e17d6d60c2c 100644
Binary files a/test/image/baselines/21.png and b/test/image/baselines/21.png differ
diff --git a/test/image/baselines/contour_heatmap_coloring.png b/test/image/baselines/contour_heatmap_coloring.png
index 48141cc3b60..dd408d1120a 100644
Binary files a/test/image/baselines/contour_heatmap_coloring.png and b/test/image/baselines/contour_heatmap_coloring.png differ
diff --git a/test/image/baselines/geo_first.png b/test/image/baselines/geo_first.png
index 7f4be6e3486..3929fca1fad 100644
Binary files a/test/image/baselines/geo_first.png and b/test/image/baselines/geo_first.png differ
diff --git a/test/image/baselines/ternary_array_styles.png b/test/image/baselines/ternary_array_styles.png
index 521df1ebcd9..ab11c0f648d 100644
Binary files a/test/image/baselines/ternary_array_styles.png and b/test/image/baselines/ternary_array_styles.png differ
diff --git a/test/image/baselines/zsmooth_methods.png b/test/image/baselines/zsmooth_methods.png
index e310acde0f9..baf8c7e3da8 100644
Binary files a/test/image/baselines/zsmooth_methods.png and b/test/image/baselines/zsmooth_methods.png differ
diff --git a/test/jasmine/tests/colorbar_test.js b/test/jasmine/tests/colorbar_test.js
index 0b6591f0e5c..0c722327cb1 100644
--- a/test/jasmine/tests/colorbar_test.js
+++ b/test/jasmine/tests/colorbar_test.js
@@ -1,4 +1,7 @@
+var Plotly = require('@lib/index');
 var Colorbar = require('@src/components/colorbar');
+var createGraphDiv = require('../assets/create_graph_div');
+var destroyGraphDiv = require('../assets/destroy_graph_div');
 
 
 describe('Test colorbar:', function() {
@@ -29,4 +32,28 @@ describe('Test colorbar:', function() {
             expect(hasColorbar(trace.marker.line)).toBe(false);
         });
     });
+
+    describe('floating point limits', function() {
+        var gd;
+
+        beforeEach(function() {
+            gd = createGraphDiv();
+        });
+
+        afterEach(destroyGraphDiv);
+
+        it('does not lock up on tiny fractional ranges', function(done) {
+            var z = [
+                [9607345622458638.0, 9607345622458652.0, 9607345622458652.0, 9607345622458646.0, 9607345622458652.0, 9607345622458650.0, 9607345622458650.0, 9607345622458646.0],
+                [9607345622458654.0, 9607345622458640.0, 9607345622458650.0, 9607345622458652.0, 9607345622458652.0, 9607345622458654.0, 9607345622458650.0, 9607345622458652.0],
+                [9607345622458654.0, 9607345622458652.0, 9607345622458638.0, 9607345622458652.0, 9607345622458650.0, 9607345622458652.0, 9607345622458654.0, 9607345622458650.0],
+                [9607345622458650.0, 9607345622458652.0, 9607345622458650.0, 9607345622458632.0, 9607345622458644.0, 9607345622458646.0, 9607345622458646.0, 9607345622458650.0],
+                [9607345622458654.0, 9607345622458652.0, 9607345622458650.0, 9607345622458650.0, 9607345622458638.0, 9607345622458654.0, 9607345622458654.0, 9607345622458650.0],
+                [9607345622458650.0, 9607345622458654.0, 9607345622458650.0, 9607345622458646.0, 9607345622458652.0, 9607345622458638.0, 9607345622458646.0, 9607345622458652.0],
+                [9607345622458654.0, 9607345622458652.0, 9607345622458654.0, 9607345622458650.0, 9607345622458654.0, 9607345622458652.0, 9607345622458640.0, 9607345622458654.0],
+                [9607345622458650.0, 9607345622458652.0, 9607345622458650.0, 9607345622458652.0, 9607345622458650.0, 9607345622458654.0, 9607345622458654.0, 9607345622458638.0]
+            ];
+            Plotly.newPlot(gd, [{type: 'heatmap', z: z}]).then(done);
+        });
+    });
 });