diff --git a/app/main/static/js/charges.js b/app/main/static/js/charges.js
index ed49471..acd66a2 100644
--- a/app/main/static/js/charges.js
+++ b/app/main/static/js/charges.js
@@ -136,7 +136,7 @@ function build_chart(div_selector, data_url, project_name, category) {
 
         var y_max = d3.max(data, function (d) {
             return d3.max(categories, function (c) {
-                return  +d[c]
+                return +d[c]
             })
         });
         y_max = y_max * height_ratio
@@ -153,9 +153,7 @@ function build_chart(div_selector, data_url, project_name, category) {
             .data(data)
             .enter()
             .append("g")
-            .attr("transform", function (d) {
-                return "translate(" + xScale(d.period) + ",0)";
-            })
+            .attr("transform", d => "translate(" + xScale(d.period) + ",0)")
             .selectAll("rect")
             .data(function (d) {
                 return categories.map(function (key) {
@@ -163,19 +161,11 @@ function build_chart(div_selector, data_url, project_name, category) {
                 });
             })
             .enter().append("rect")
-            .attr("x", function (d) {
-                return xCategories(d.key);
-            })
-            .attr("y", function (d) {
-                return yScale(d.value);
-            })
+            .attr("x", d => xCategories(d.key))
+            .attr("y", d => yScale(d.value))
             .attr("width", xCategories.bandwidth())
-            .attr("height", function (d) {
-                return height - yScale(d.value);
-            })
-            .attr("fill", function (d) {
-                return colorScale(d.key);
-            });
+            .attr("height", d => height - yScale(d.value))
+            .attr("fill", d => colorScale(d.key));
 
     }
 
--
libgit2 0.21.2