diff --git a/core/src/main/resources/hudson/Messages_de.properties b/core/src/main/resources/hudson/Messages_de.properties
index d524a518cd..4ad4596e17 100644
--- a/core/src/main/resources/hudson/Messages_de.properties
+++ b/core/src/main/resources/hudson/Messages_de.properties
@@ -67,6 +67,7 @@ PluginWrapper.PluginWrapperAdministrativeMonitor.DisplayName=Plugin-Ladefehler
 
 ProxyConfiguration.FailedToConnectViaProxy=Konnte nicht mit {0} verbinden.
 ProxyConfiguration.FailedToConnect=Konnte nicht mit {0} verbinden (code {1}).
+ProxyConfiguration.NonTLSWarning=Jenkins unterstützt nur die Verwendung einer HTTP-Verbindung zum Proxy. Die Zugangsdaten könnten für andere im selben Netzwerk sichtbar sein.
 ProxyConfiguration.MalformedTestUrl=Format der Test-URL ungültig
 ProxyConfiguration.Success=Erfolg (code {0})
 ProxyConfiguration.TestUrlRequired=Test-URL muss angegeben werden.
diff --git a/core/src/main/resources/hudson/ProxyConfiguration/config.groovy b/core/src/main/resources/hudson/ProxyConfiguration/config.groovy
deleted file mode 100644
index 64f827a9ca..0000000000
--- a/core/src/main/resources/hudson/ProxyConfiguration/config.groovy
+++ /dev/null
@@ -1,32 +0,0 @@
-package hudson.ProxyConfiguration
-
-def f=namespace(lib.FormTagLib)
-def l=namespace(lib.LayoutTagLib)
-
-set("readOnlyMode", !app.hasPermission(app.ADMINISTER))
-
-f.entry(title:_("Server"),field:"name") {
-    f.textbox()
-}
-f.entry(title:_("Port"),field:"port") {
-    f.number(clazz:"number",min:0,max:65535,step:1)
-}
-f.entry(title:_("User name"),field:"userName") {
-    f.textbox()
-}
-f.entry(title:_("Password"),field:"secretPassword") {
-    f.password()
-}
-f.entry(title:_("No Proxy Host"),field:"noProxyHost") {
-    f.textarea()
-}
-
-l.isAdmin() {
-    f.advanced() {
-        f.entry(title: _("Test URL"), field: "testUrl") {
-            f.textbox()
-        }
-        f.validateButton(title:_("Validate Proxy"),
-                         method:"validateProxy", with:"testUrl,name,port,userName,secretPassword,noProxyHost")
-    }
-}
diff --git a/core/src/main/resources/hudson/ProxyConfiguration/config.jelly b/core/src/main/resources/hudson/ProxyConfiguration/config.jelly
new file mode 100644
index 0000000000..e6e9ff33a4
--- /dev/null
+++ b/core/src/main/resources/hudson/ProxyConfiguration/config.jelly
@@ -0,0 +1,48 @@
+<!--
+The MIT License
+Copyright (c) 2025, Stefan Spieker
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+-->
+
+<?jelly escape-by-default='true'?>
+<j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form" xmlns:l="/lib/layout">
+    <j:set var="readOnlyMode" value="${!app.hasPermission(app.ADMINISTER)}"/>
+    <f:entry title="${%Server}">
+        <f:textbox field="name"/>
+    </f:entry>
+    <f:entry title="${%Port}">
+        <f:number field="port" min="0" max="65535" step="1"/>
+    </f:entry>
+    <f:entry title="${%User name}">
+        <f:textbox field="userName"/>
+    </f:entry>
+    <f:entry title="${%Password}">
+        <f:password field="secretPassword"/>
+    </f:entry>
+    <f:entry title="${%No Proxy Host}">
+        <f:textarea field="noProxyHost"/>
+    </f:entry>
+
+    <l:isAdmin>
+        <f:advanced>
+            <f:entry title="${%Test URL}">
+                <f:textbox field="testUrl"/>
+            </f:entry>
+            <f:validateButton title="${%Validate Proxy}" method="validateProxy" with="testUrl,name,port,userName,secretPassword,noProxyHost"/>
+        </f:advanced>
+    </l:isAdmin>
+</j:jelly>
diff --git a/core/src/main/resources/hudson/ProxyConfiguration/config_de.properties b/core/src/main/resources/hudson/ProxyConfiguration/config_de.properties
index ec044ad190..f439a530c5 100644
--- a/core/src/main/resources/hudson/ProxyConfiguration/config_de.properties
+++ b/core/src/main/resources/hudson/ProxyConfiguration/config_de.properties
@@ -24,5 +24,6 @@ Server=Server
 Port=Port
 User\ name=Benutzername
 Password=Passwort
+Test\ URL=Test-URL
 No\ Proxy\ Host=Proxy-Ausnahmen
 Validate\ Proxy=Proxy-Konfiguration prüfen