diff --git a/client/components/ModulesTreemap.jsx b/client/components/ModulesTreemap.jsx
index ddd596e9..dd726889 100644
--- a/client/components/ModulesTreemap.jsx
+++ b/client/components/ModulesTreemap.jsx
@@ -209,7 +209,7 @@ export default class ModulesTreemap extends Component {
   handleConcatenatedModulesContentToggle = flag => {
     store.showConcatenatedModulesContent = flag;
     if (flag) {
-      localStorage.setItem('showConcatenatedModulesContent', '1');
+      localStorage.setItem('showConcatenatedModulesContent', true);
     } else {
       localStorage.removeItem('showConcatenatedModulesContent');
     }
diff --git a/client/store.js b/client/store.js
index 32c2c2cf..fa5ac88d 100644
--- a/client/store.js
+++ b/client/store.js
@@ -10,7 +10,7 @@ export class Store {
   @observable searchQuery = '';
   @observable defaultSize;
   @observable selectedSize;
-  @observable showConcatenatedModulesContent = localStorage.getItem('showConcatenatedModulesContent') === '1';
+  @observable showConcatenatedModulesContent = (localStorage.getItem('showConcatenatedModulesContent') === true);
 
   setModules(modules) {
     walkModules(modules, module => {
diff --git a/client/utils.js b/client/utils.js
index 8690eb96..70530849 100644
--- a/client/utils.js
+++ b/client/utils.js
@@ -28,16 +28,16 @@ export const localStorage = {
     }
   },
 
-  setItem(k, v) {
+  setItem(key, value) {
     try {
-      window.localStorage.setItem(k, v);
-    } catch (x) { /* ignored */ }
+      window.localStorage.setItem(`${KEY_PREFIX}.${key}`, JSON.stringify(value));
+    } catch (err) { /* ignored */ }
   },
 
-  removeItem(k) {
+  removeItem(key) {
     try {
-      window.localStorage.removeItem(k);
-    } catch (x) { /* ignored */ }
+      window.localStorage.removeItem(key);
+    } catch (err) { /* ignored */ }
   }
 
-};
\ No newline at end of file
+};