diff --git a/src/main/resources/public/lang.js b/src/main/resources/public/lang.js
new file mode 100644
index 00000000..1af2015d
--- /dev/null
+++ b/src/main/resources/public/lang.js
@@ -0,0 +1,5 @@
+function switchLang(lang) {
+    const searchParams = new URLSearchParams(window.location.search);
+    searchParams.set("lang", lang);
+    window.location.search = searchParams.toString();
+}
diff --git a/src/main/resources/public/post.js b/src/main/resources/public/post.js
new file mode 100644
index 00000000..6e8d0288
--- /dev/null
+++ b/src/main/resources/public/post.js
@@ -0,0 +1,6 @@
+window.handleState = function handleState() {
+  if (document.readyState === 'interactive' || document.readyState === "complete") {
+    document.forms[0].submit();
+  }
+};
+document.onreadystatechange = window.handleState;
diff --git a/src/main/resources/templates/consent.html b/src/main/resources/templates/consent.html
index fd2fb032..1ba1627c 100644
--- a/src/main/resources/templates/consent.html
+++ b/src/main/resources/templates/consent.html
@@ -138,13 +138,5 @@ <h1 th:text="#{footerTitle}"></h1>
     </div>
 </div>
 </body>
-<script>
-
-  function switchLang(lang) {
-    const searchParams = new URLSearchParams(window.location.search);
-    searchParams.set("lang", lang);
-    window.location.search = searchParams.toString();
-  }
-
-</script>
-</html>
\ No newline at end of file
+<script th:src="@{/lang.js}"></script>
+</html>
diff --git a/src/main/resources/templates/device_continue.html b/src/main/resources/templates/device_continue.html
index 42313e49..ebc51356 100644
--- a/src/main/resources/templates/device_continue.html
+++ b/src/main/resources/templates/device_continue.html
@@ -37,13 +37,5 @@ <h1 th:text="#{authenticated}"></h1>
 
 </div>
 </body>
-<script>
-
-    function switchLang(lang) {
-        const searchParams = new URLSearchParams(window.location.search);
-        searchParams.set("lang", lang);
-        window.location.search = searchParams.toString();
-    }
-
-</script>
-</html>
\ No newline at end of file
+<script th:src="@{/lang.js}"></script>
+</html>
diff --git a/src/main/resources/templates/device_error.html b/src/main/resources/templates/device_error.html
index c01cc60a..900b583c 100644
--- a/src/main/resources/templates/device_error.html
+++ b/src/main/resources/templates/device_error.html
@@ -37,13 +37,5 @@ <h1 th:text="#{notAuthenticated}"></h1>
 
 </div>
 </body>
-<script>
-
-    function switchLang(lang) {
-        const searchParams = new URLSearchParams(window.location.search);
-        searchParams.set("lang", lang);
-        window.location.search = searchParams.toString();
-    }
-
-</script>
-</html>
\ No newline at end of file
+<script th:src="@{/lang.js}"></script>
+</html>
diff --git a/src/main/resources/templates/form_post.html b/src/main/resources/templates/form_post.html
index 7c696f2c..cb8c1ff9 100644
--- a/src/main/resources/templates/form_post.html
+++ b/src/main/resources/templates/form_post.html
@@ -1,6 +1,6 @@
 <html xmlns:th="http://www.thymeleaf.org">
 <head><title>Submit This Form</title></head>
-<body onload="javascript:document.forms[0].submit()" enctype="application/x-www-form-urlencoded">
+<body enctype="application/x-www-form-urlencoded">
 <form method="post" th:action="${redirect_uri}">
     <input th:if="${access_token != null}" type="hidden" name="access_token" th:value="${access_token}"/>
     <input th:if="${code != null}" type="hidden" name="code" th:value="${code}"/>
@@ -10,4 +10,5 @@
     <input th:if="${error_description != null}" type="hidden" name="error_description" th:value="${error_description}"/>
 </form>
 </body>
-</html>
\ No newline at end of file
+<script th:src="@{/post.js}"></script>
+</html>
diff --git a/src/main/resources/templates/no_session_found.html b/src/main/resources/templates/no_session_found.html
index 5960c732..0c1d1a8b 100644
--- a/src/main/resources/templates/no_session_found.html
+++ b/src/main/resources/templates/no_session_found.html
@@ -63,8 +63,8 @@ <h1 class="error-title__heading">Error - No session found</h1>
 
 
 
-<script src="/application.min.js" type="text/javascript"></script>
+<script src="/application.min.js"></script>
 
 
 
-</body></html>
\ No newline at end of file
+</body></html>
diff --git a/src/main/resources/templates/no_session_found_nl.html b/src/main/resources/templates/no_session_found_nl.html
index 6c8bc4f5..c050b09c 100644
--- a/src/main/resources/templates/no_session_found_nl.html
+++ b/src/main/resources/templates/no_session_found_nl.html
@@ -65,8 +65,8 @@ <h1 class="error-title__heading">Fout - Geen sessie gevonden</h1>
 
 
 
-<script src="/application.min.js" type="text/javascript"></script>
+<script src="/application.min.js"></script>
 
 
 
-</body></html>
\ No newline at end of file
+</body></html>
diff --git a/src/main/resources/templates/verify.html b/src/main/resources/templates/verify.html
index ddd48b2f..37b103b1 100644
--- a/src/main/resources/templates/verify.html
+++ b/src/main/resources/templates/verify.html
@@ -82,14 +82,6 @@ <h1 th:text="#{footerTitle}"></h1>
     </div>
 </div>
 </body>
-<script th:src="@{/main.js}" type="text/javascript"></script>
-<script>
-
-    function switchLang(lang) {
-        const searchParams = new URLSearchParams(window.location.search);
-        searchParams.set("lang", lang);
-        window.location.search = searchParams.toString();
-    }
-
-</script>
-</html>
\ No newline at end of file
+<script th:src="@{/main.js}"></script>
+<script th:src="@{/lang.js}"></script>
+</html>
