--- a/devtools/client/netmonitor/src/components/RequestListColumnTransferredSize.js
+++ b/devtools/client/netmonitor/src/components/RequestListColumnTransferredSize.js
@@ -7,17 +7,19 @@
 const { Component } = require("devtools/client/shared/vendor/react");
 const dom = require("devtools/client/shared/vendor/react-dom-factories");
 const PropTypes = require("devtools/client/shared/vendor/react-prop-types");
 const { getFormattedSize } = require("../utils/format-utils");
 const { L10N } = require("../utils/l10n");
 const { propertiesEqual } = require("../utils/request-utils");
 
 const { div } = dom;
-
+const SIZE_CACHED = L10N.getStr("networkMenu.sizeCached");
+const SIZE_SERVICE_WORKER = L10N.getStr("networkMenu.sizeServiceWorker");
+const SIZE_UNAVAILABLE = L10N.getStr("networkMenu.sizeUnavailable");
 const UPDATED_TRANSFERRED_PROPS = [
   "transferredSize",
   "fromCache",
   "fromServiceWorker",
 ];
 
 class RequestListColumnTransferredSize extends Component {
   static get propTypes() {
@@ -30,23 +32,23 @@ class RequestListColumnTransferredSize e
     return !propertiesEqual(UPDATED_TRANSFERRED_PROPS, this.props.item, nextProps.item);
   }
 
   render() {
     let { fromCache, fromServiceWorker, status, transferredSize } = this.props.item;
     let text;
 
     if (fromCache || status === "304") {
-      text = L10N.getStr("networkMenu.sizeCached");
+      text = SIZE_CACHED;
     } else if (fromServiceWorker) {
-      text = L10N.getStr("networkMenu.sizeServiceWorker");
+      text = SIZE_SERVICE_WORKER;
     } else if (typeof transferredSize == "number") {
       text = getFormattedSize(transferredSize);
     } else if (transferredSize === null) {
-      text = L10N.getStr("networkMenu.sizeUnavailable");
+      text = SIZE_UNAVAILABLE;
     }
 
     return (
       div({ className: "requests-list-column requests-list-transferred", title: text },
         text
       )
     );
   }