diff --git a/src/static/js/ChangesetUtils.js b/src/static/js/ChangesetUtils.js
index c7333afcf..67923150b 100644
--- a/src/static/js/ChangesetUtils.js
+++ b/src/static/js/ChangesetUtils.js
@@ -1,3 +1,4 @@
+'use strict';
 /**
  * This module contains several helper Functions to build Changesets
  * based on a SkipList
@@ -18,7 +19,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-exports.buildRemoveRange = function (rep, builder, start, end) {
+exports.buildRemoveRange = (rep, builder, start, end) => {
   const startLineOffset = rep.lines.offsetOfIndex(start[0]);
   const endLineOffset = rep.lines.offsetOfIndex(end[0]);
 
@@ -30,7 +31,7 @@ exports.buildRemoveRange = function (rep, builder, start, end) {
   }
 };
 
-exports.buildKeepRange = function (rep, builder, start, end, attribs, pool) {
+exports.buildKeepRange = (rep, builder, start, end, attribs, pool) => {
   const startLineOffset = rep.lines.offsetOfIndex(start[0]);
   const endLineOffset = rep.lines.offsetOfIndex(end[0]);
 
@@ -42,7 +43,7 @@ exports.buildKeepRange = function (rep, builder, start, end, attribs, pool) {
   }
 };
 
-exports.buildKeepToStartOfRange = function (rep, builder, start) {
+exports.buildKeepToStartOfRange = (rep, builder, start) => {
   const startLineOffset = rep.lines.offsetOfIndex(start[0]);
 
   builder.keep(startLineOffset, start[0]);