diff --git a/Gruntfile.js b/Gruntfile.js
index 99fcd04..c508723 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -1,4 +1,6 @@
 module.exports = function (grunt) {
+  "use strict";
+
   grunt.loadTasks("tasks");
 
   grunt.registerTask("default", ["bower-install-simple", "lint", "copy", "sass", "postcss", "requirejs:default", "inline"]);
diff --git a/app.js b/app.js
index d6a1227..f2d4e3c 100644
--- a/app.js
+++ b/app.js
@@ -1,3 +1,5 @@
+"use strict";
+
 require.config({
   baseUrl: "lib",
   paths: {
diff --git a/bower.json b/bower.json
index 69d1b13..8233913 100644
--- a/bower.json
+++ b/bower.json
@@ -18,7 +18,7 @@
     "es6-shim": "~0.35.1",
     "almond": "~0.3.2",
     "d3": "~3.5.17",
-    "roboto-fontface": "~0.3.0",
+    "roboto-fontface": "~0.4.5",
     "virtual-dom": "~2.1.1",
     "leaflet-providers": "~1.1.10",
     "rbush": "https://github.com/mourner/rbush.git#~1.4.3"
diff --git a/lib/about.js b/lib/about.js
index 2a20ae5..9222794 100644
--- a/lib/about.js
+++ b/lib/about.js
@@ -1,4 +1,6 @@
 define(function () {
+  "use strict";
+
   return function () {
     this.render = function (d) {
       var el = document.createElement("div");
diff --git a/lib/container.js b/lib/container.js
index 4f32a84..d799167 100644
--- a/lib/container.js
+++ b/lib/container.js
@@ -1,4 +1,6 @@
 define([], function () {
+  "use strict";
+
   return function (tag) {
     if (!tag) {
       tag = "div";
diff --git a/lib/datadistributor.js b/lib/datadistributor.js
index 3edeaf6..ea79341 100644
--- a/lib/datadistributor.js
+++ b/lib/datadistributor.js
@@ -1,4 +1,6 @@
 define(["filters/nodefilter"], function (NodeFilter) {
+  "use strict";
+
   return function () {
     var targets = [];
     var filterObservers = [];
diff --git a/lib/filters/filtergui.js b/lib/filters/filtergui.js
index 10629d7..4db1b4b 100644
--- a/lib/filters/filtergui.js
+++ b/lib/filters/filtergui.js
@@ -1,4 +1,6 @@
-define([], function () {
+define(function () {
+  "use strict";
+
   return function (distributor) {
     var container = document.createElement("ul");
     container.classList.add("filters");
diff --git a/lib/filters/genericnode.js b/lib/filters/genericnode.js
index c4fe7a9..253c38b 100644
--- a/lib/filters/genericnode.js
+++ b/lib/filters/genericnode.js
@@ -1,4 +1,6 @@
 define(["helper"], function (helper) {
+  "use strict";
+
   return function (name, key, value, f) {
     var negate = false;
     var refresh;
diff --git a/lib/filters/nodefilter.js b/lib/filters/nodefilter.js
index 1d6bf5f..68da159 100644
--- a/lib/filters/nodefilter.js
+++ b/lib/filters/nodefilter.js
@@ -1,4 +1,6 @@
-define([], function () {
+define(function () {
+  "use strict";
+
   return function (filter) {
     return function (data) {
       var n = Object.create(data);
diff --git a/lib/forcegraph.js b/lib/forcegraph.js
index 645b053..a113345 100644
--- a/lib/forcegraph.js
+++ b/lib/forcegraph.js
@@ -1,4 +1,6 @@
 define(["d3", "helper"], function (d3, helper) {
+  "use strict";
+
   var margin = 200;
   var NODE_RADIUS = 15;
   var LINE_RADIUS = 7;
diff --git a/lib/gui.js b/lib/gui.js
index f8427ed..10c3bb2 100644
--- a/lib/gui.js
+++ b/lib/gui.js
@@ -5,6 +5,8 @@ define(["chroma-js", "map", "sidebar", "tabs", "container", "meshstats",
   function (chroma, Map, Sidebar, Tabs, Container, Meshstats, Legend, Linklist,
             Nodelist, SimpleNodelist, Infobox, Proportions, ForceGraph,
             Title, About, DataDistributor, FilterGUI) {
+    "use strict";
+
     return function (config, router) {
       var self = this;
       var content;
diff --git a/lib/infobox/link.js b/lib/infobox/link.js
index d24e144..8cfe683 100644
--- a/lib/infobox/link.js
+++ b/lib/infobox/link.js
@@ -1,4 +1,6 @@
 define(["helper"], function (helper) {
+  "use strict";
+
   function showStatImg(o, d) {
     var subst = {};
     subst["{SOURCE}"] = d.source.node_id;
diff --git a/lib/infobox/location.js b/lib/infobox/location.js
index 4695ac4..fe40011 100644
--- a/lib/infobox/location.js
+++ b/lib/infobox/location.js
@@ -1,4 +1,6 @@
 define(["helper"], function (helper) {
+  "use strict";
+
   return function (config, el, router, d) {
     var sidebarTitle = document.createElement("h2");
     sidebarTitle.textContent = "Location: " + d.toString();
diff --git a/lib/infobox/main.js b/lib/infobox/main.js
index 8f1ef4a..9690a2a 100644
--- a/lib/infobox/main.js
+++ b/lib/infobox/main.js
@@ -1,4 +1,6 @@
 define(["infobox/link", "infobox/node", "infobox/location"], function (Link, Node, Location) {
+  "use strict";
+
   return function (config, sidebar, router) {
     var self = this;
     var el;
diff --git a/lib/infobox/node.js b/lib/infobox/node.js
index 6839206..b6fcdac 100644
--- a/lib/infobox/node.js
+++ b/lib/infobox/node.js
@@ -1,5 +1,7 @@
 define(["moment", "tablesort", "helper", "moment.de"],
   function (moment, Tablesort, helper) {
+    "use strict";
+
     function showGeoURI(d) {
       function showLatitude(d) {
         var suffix = Math.sign(d) > -1 ? "' N" : "' S";
diff --git a/lib/legend.js b/lib/legend.js
index b01782f..20c0e97 100644
--- a/lib/legend.js
+++ b/lib/legend.js
@@ -1,4 +1,6 @@
 define(function () {
+  "use strict";
+
   return function () {
     var self = this;
 
diff --git a/lib/linklist.js b/lib/linklist.js
index 661b777..0bf6d7e 100644
--- a/lib/linklist.js
+++ b/lib/linklist.js
@@ -1,4 +1,6 @@
 define(["sorttable", "virtual-dom", "helper"], function (SortTable, V, helper) {
+  "use strict";
+
   function linkName(d) {
     return (d.source.node ? d.source.node.nodeinfo.hostname : d.source.id) + " – " + d.target.node.nodeinfo.hostname;
   }
diff --git a/lib/locationmarker.js b/lib/locationmarker.js
index 0f8c35a..a4a596f 100644
--- a/lib/locationmarker.js
+++ b/lib/locationmarker.js
@@ -1,4 +1,6 @@
 define(["leaflet"], function (L) {
+  "use strict";
+
   return L.CircleMarker.extend({
     outerCircle: {
       stroke: false,
diff --git a/lib/main.js b/lib/main.js
index 36d421c..693191c 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -1,5 +1,7 @@
 define(["moment", "router", "leaflet", "gui", "helper", "moment.de"],
   function (moment, Router, L, GUI, helper) {
+    "use strict";
+
     return function (config) {
       function handleData(data) {
         var dataNodes = {};
diff --git a/lib/map.js b/lib/map.js
index f099fb6..0bc17cb 100644
--- a/lib/map.js
+++ b/lib/map.js
@@ -2,6 +2,8 @@ define(["map/clientlayer", "map/labelslayer",
     "d3", "leaflet", "moment", "locationmarker", "rbush", "helper",
     "leaflet.label", "leaflet.providers", "moment.de"],
   function (ClientLayer, LabelsLayer, d3, L, moment, LocationMarker, rbush, helper) {
+    "use strict";
+
     var options = {
       worldCopyJump: true,
       zoomControl: false
diff --git a/lib/map/clientlayer.js b/lib/map/clientlayer.js
index 7579f4e..1dc8cb7 100644
--- a/lib/map/clientlayer.js
+++ b/lib/map/clientlayer.js
@@ -1,5 +1,6 @@
 define(["leaflet"],
   function (L) {
+    "use strict";
 
     return L.TileLayer.Canvas.extend({
       setData: function (d) {
diff --git a/lib/map/labelslayer.js b/lib/map/labelslayer.js
index a6af979..d54c4af 100644
--- a/lib/map/labelslayer.js
+++ b/lib/map/labelslayer.js
@@ -1,5 +1,7 @@
 define(["leaflet", "rbush"],
   function (L, rbush) {
+    "use strict";
+
     var labelLocations = [["left", "middle", 0 / 8],
       ["center", "top", 6 / 8],
       ["right", "middle", 4 / 8],
diff --git a/lib/meshstats.js b/lib/meshstats.js
index bc6c025..dd1d1f7 100644
--- a/lib/meshstats.js
+++ b/lib/meshstats.js
@@ -1,4 +1,6 @@
 define(["helper"], function (helper) {
+  "use strict";
+
   return function (config) {
     var self = this;
     var stats, timestamp;
diff --git a/lib/nodelist.js b/lib/nodelist.js
index 12687c4..471aba4 100644
--- a/lib/nodelist.js
+++ b/lib/nodelist.js
@@ -1,4 +1,6 @@
 define(["sorttable", "virtual-dom", "helper"], function (SortTable, V, helper) {
+  "use strict";
+
   function getUptime(now, d) {
     if (d.flags.online && "uptime" in d.statistics) {
       return Math.round(d.statistics.uptime);
diff --git a/lib/proportions.js b/lib/proportions.js
index 391145e..d8a9cda 100644
--- a/lib/proportions.js
+++ b/lib/proportions.js
@@ -1,5 +1,6 @@
 define(["chroma-js", "virtual-dom", "filters/genericnode", "helper"],
   function (Chroma, V, Filter, helper) {
+    "use strict";
 
     return function (config, filterManager) {
       var self = this;
diff --git a/lib/router.js b/lib/router.js
index d841d32..7c9fc4a 100644
--- a/lib/router.js
+++ b/lib/router.js
@@ -1,4 +1,6 @@
 define(["helper"], function (helper) {
+  "use strict";
+
   return function () {
     var self = this;
     var objects = {nodes: {}, links: {}};
diff --git a/lib/sidebar.js b/lib/sidebar.js
index 4c839cc..f644c6e 100644
--- a/lib/sidebar.js
+++ b/lib/sidebar.js
@@ -1,4 +1,6 @@
-define([], function () {
+define(function () {
+  "use strict";
+
   return function (el) {
     var self = this;
 
diff --git a/lib/simplenodelist.js b/lib/simplenodelist.js
index 2ba0207..be480d1 100644
--- a/lib/simplenodelist.js
+++ b/lib/simplenodelist.js
@@ -1,4 +1,6 @@
 define(["moment", "virtual-dom", "helper", "moment.de"], function (moment, V, helper) {
+  "use strict";
+
   return function (nodes, field, router, title) {
     var self = this;
     var el, tbody;
diff --git a/lib/sorttable.js b/lib/sorttable.js
index 881efba..2fc7353 100644
--- a/lib/sorttable.js
+++ b/lib/sorttable.js
@@ -1,4 +1,6 @@
 define(["virtual-dom"], function (V) {
+  "use strict";
+
   return function (headings, sortIndex, renderRow) {
     var data;
     var sortReverse = false;
diff --git a/lib/tabs.js b/lib/tabs.js
index f4fed6d..701af29 100644
--- a/lib/tabs.js
+++ b/lib/tabs.js
@@ -1,4 +1,6 @@
-define([], function () {
+define(function () {
+  "use strict";
+
   return function () {
     var self = this;
 
diff --git a/lib/title.js b/lib/title.js
index 4c99c2c..243c6bd 100644
--- a/lib/title.js
+++ b/lib/title.js
@@ -1,4 +1,6 @@
 define(function () {
+  "use strict";
+
   return function (config) {
     function setTitle(d) {
       var title = [config.siteName];
diff --git a/lib/utils/helper.js b/lib/utils/helper.js
index e3dce69..7a568c3 100644
--- a/lib/utils/helper.js
+++ b/lib/utils/helper.js
@@ -1,3 +1,5 @@
+"use strict";
+
 define({
   get: function (url) {
     return new Promise(function (resolve, reject) {
@@ -77,7 +79,7 @@ define({
   },
 
   listReplace: function (s, subst) {
-    for (key in subst) {
+    for (var key in subst) {
       var re = new RegExp(key, "g");
       s = s.replace(re, subst[key]);
     }
diff --git a/tasks/build.js b/tasks/build.js
index 3a70fe8..4701cfb 100644
--- a/tasks/build.js
+++ b/tasks/build.js
@@ -1,4 +1,6 @@
 module.exports = function (grunt) {
+  "use strict";
+
   grunt.config.merge({
     bowerdir: "bower_components",
     copy: {
diff --git a/tasks/clean.js b/tasks/clean.js
index ed0e234..67181e0 100644
--- a/tasks/clean.js
+++ b/tasks/clean.js
@@ -1,4 +1,6 @@
 module.exports = function (grunt) {
+  "use strict";
+
   grunt.config.merge({
     clean: {
       build: ["build/**/*", "node_modules/grunt-newer/.cache"]
diff --git a/tasks/development.js b/tasks/development.js
index e9b312e..938cd87 100644
--- a/tasks/development.js
+++ b/tasks/development.js
@@ -1,4 +1,6 @@
 module.exports = function (grunt) {
+  "use strict";
+
   grunt.config.merge({
     connect: {
       server: {
diff --git a/tasks/linting.js b/tasks/linting.js
index 5409fd5..6667d68 100644
--- a/tasks/linting.js
+++ b/tasks/linting.js
@@ -1,4 +1,6 @@
 module.exports = function (grunt) {
+  "use strict";
+
   grunt.config.merge({
     checkDependencies: {
       options: {