diff --git a/src/exercises/_final.html b/src/exercises/_final.html
index 9528dff..2c07eed 100644
--- a/src/exercises/_final.html
+++ b/src/exercises/_final.html
@@ -1,4 +1,4 @@
-<!DOCTYPE html>
+﻿<!DOCTYPE html>
 <html>
   <head>
     <meta charset="utf-8" />
@@ -8,7 +8,7 @@
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <link rel="stylesheet" href="http://geoext.github.io/geoext3/v3.0.0/resources/css/gx-popup.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
     <style>
 .gx-popup p {
   padding: 5px 5px 0 5px;
diff --git a/src/feature-grid/create.md b/src/feature-grid/create.md
index 7b70abd..1fd2015 100644
--- a/src/feature-grid/create.md
+++ b/src/feature-grid/create.md
@@ -16,7 +16,7 @@ Now it's time to change the grid to no longer show static data from [The Simpson
     <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
   </head>
   <body>
     <script>
diff --git a/src/feature-grid/prepare-layout.md b/src/feature-grid/prepare-layout.md
index 5d33f2c..4fb215b 100644
--- a/src/feature-grid/prepare-layout.md
+++ b/src/feature-grid/prepare-layout.md
@@ -16,7 +16,7 @@ Now we want to add a grid panel to our basic map application.
     <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
   </head>
   <body>
     <script>
diff --git a/src/first-steps/hello-geoext.md b/src/first-steps/hello-geoext.md
index a48dd1a..93b8fd2 100644
--- a/src/first-steps/hello-geoext.md
+++ b/src/first-steps/hello-geoext.md
@@ -40,7 +40,7 @@ Ext.onReady(function(){
 <script src="./lib/ol/ol.js"></script>
 ```
 
-* Add the JavaScript for GeoExt: `https://geoext.github.io/geoext3/v3.0.0/GeoExt.js`
+* Add the JavaScript for GeoExt: `https://geoext.github.io/geoext3/v3.1.0/GeoExt.js`
 
 * Most GeoExt components don't need special CSS. If you use the `Popup`-components, you may want to include the following CSS file: `https://geoext.github.io/geoext3/v3.0.0/resources/css/gx-popup.css`
 
diff --git a/src/layer-tree/add-layerstree-store.md b/src/layer-tree/add-layerstree-store.md
index b5923fc..02e5725 100644
--- a/src/layer-tree/add-layerstree-store.md
+++ b/src/layer-tree/add-layerstree-store.md
@@ -19,7 +19,7 @@ In order to do this, we need to change the store that is used for the tree. Inst
     <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
   </head>
   <body>
     <script>
diff --git a/src/layer-tree/prepare-layout.md b/src/layer-tree/prepare-layout.md
index d8a6827..4085a1b 100644
--- a/src/layer-tree/prepare-layout.md
+++ b/src/layer-tree/prepare-layout.md
@@ -16,7 +16,7 @@ The previous chapter started from the following template, which we now want to r
     <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
   </head>
   <body>
     <script>
diff --git a/src/map-component/basic-example.md b/src/map-component/basic-example.md
index 9397736..afa5773 100644
--- a/src/map-component/basic-example.md
+++ b/src/map-component/basic-example.md
@@ -16,7 +16,7 @@ We want to have a look at a fully working example first.
       <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
       <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
       <script src="./lib/ol/ol.js"></script>
-      <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+      <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
     </head>
     <body>
       <script>
diff --git a/src/map-component/dissecting-example.md b/src/map-component/dissecting-example.md
index 7f9b6a2..4e925db 100644
--- a/src/map-component/dissecting-example.md
+++ b/src/map-component/dissecting-example.md
@@ -16,7 +16,7 @@ The HTML of the page looks as follows:
     <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
   </head>
   <body>
     <script>
diff --git a/src/other/overview-map.md b/src/other/overview-map.md
index 8da8d2d..a9658fb 100644
--- a/src/other/overview-map.md
+++ b/src/other/overview-map.md
@@ -17,7 +17,7 @@ Especially when zoomed in, it can be hard to understand the extent of the mappan
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <link rel="stylesheet" href="https://geoext.github.io/geoext3/v3.0.0/resources/css/gx-popup.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
     <style>
 .gx-popup p {
   padding: 5px 5px 0 5px;
diff --git a/src/other/popups.md b/src/other/popups.md
index 3bc0f4f..6f732e3 100644
--- a/src/other/popups.md
+++ b/src/other/popups.md
@@ -16,7 +16,7 @@ In this chapter we want to add short informative popups on the map. We will open
     <script src="https://cdnjs.cloudflare.com/ajax/libs/extjs/6.2.0/ext-all.js"></script>
     <link rel="stylesheet" href="./lib/ol/ol.css" type="text/css" />
     <script src="./lib/ol/ol.js"></script>
-    <script src="https://geoext.github.io/geoext3/v3.0.0/GeoExt.js"></script>
+    <script src="https://geoext.github.io/geoext3/v3.1.0/GeoExt.js"></script>
   </head>
   <body>
     <script>
