diff --git a/layout-templates/org.kde.plasma.desktop.defaultPanel/contents/layout.js b/layout-templates/org.kde.plasma.desktop.defaultPanel/contents/layout.js
index 048671ef4..f541725a8 100644
--- a/layout-templates/org.kde.plasma.desktop.defaultPanel/contents/layout.js
+++ b/layout-templates/org.kde.plasma.desktop.defaultPanel/contents/layout.js
@@ -1,84 +1,97 @@
 var panel = new Panel
 var panelScreen = panel.screen
 var freeEdges = {"bottom": true, "top": true, "left": true, "right": true}
 
 for (i = 0; i < panelIds.length; ++i) {
     var tmpPanel = panelById(panelIds[i])
     if (tmpPanel.screen == panelScreen) {
         // Ignore the new panel
         if (tmpPanel.id != panel.id) {
             freeEdges[tmpPanel.location] = false;
         }
     }
 }
 
 if (freeEdges["bottom"] == true) {
     panel.location = "bottom";
 } else if (freeEdges["top"] == true) {
     panel.location = "top";
 } else if (freeEdges["left"] == true) {
     panel.location = "left";
 } else if (freeEdges["right"] == true) {
     panel.location = "right";
 } else {
     // There is no free edge, so leave the default value
     panel.location = "top";
 }
 
 panel.height = gridUnit * 2
 
+// Restrict horizontal panel to a maximum size of a 21:9 monitor
+const maximumAspectRatio = 21/9;
+if (panel.formFactor === "horizontal") {
+    const geo = screenGeometry(panelScreen);
+    const maximumWidth = Math.ceil(geo.height * maximumAspectRatio);
+
+    if (geo.width > maximumWidth) {
+        panel.alignment = "center";
+        panel.minimumLength = maximumWidth;
+        panel.maximumLength = maximumWidth;
+    }
+}
+
 var kickoff = panel.addWidget("org.kde.plasma.kickoff")
 kickoff.currentConfigGroup = ["Shortcuts"]
 kickoff.writeConfig("global", "Alt+F1")
 
 //panel.addWidget("org.kde.plasma.showActivityManager")
 panel.addWidget("org.kde.plasma.pager")
 panel.addWidget("org.kde.plasma.taskmanager")
 
 /* Next up is determining whether to add the Input Method Panel
  * widget to the panel or not. This is done based on whether
  * the system locale's language id is a member of the following
  * white list of languages which are known to pull in one of
  * our supported IME backends when chosen during installation
  * of common distributions. */
 
 var langIds = ["as",    // Assamese
                "bn",    // Bengali
                "bo",    // Tibetan
                "brx",   // Bodo
                "doi",   // Dogri
                "gu",    // Gujarati
                "hi",    // Hindi
                "ja",    // Japanese
                "kn",    // Kannada
                "ko",    // Korean
                "kok",   // Konkani
                "ks",    // Kashmiri
                "lep",   // Lepcha
                "mai",   // Maithili
                "ml",    // Malayalam
                "mni",   // Manipuri
                "mr",    // Marathi
                "ne",    // Nepali
                "or",    // Odia
                "pa",    // Punjabi
                "sa",    // Sanskrit
                "sat",   // Santali
                "sd",    // Sindhi
                "si",    // Sinhala
                "ta",    // Tamil
                "te",    // Telugu
                "th",    // Thai
                "ur",    // Urdu
                "vi",    // Vietnamese
                "zh_CN", // Simplified Chinese
                "zh_TW"] // Traditional Chinese
 
 if (langIds.indexOf(languageId) != -1) {
     panel.addWidget("org.kde.plasma.kimpanel");
 }
 
 panel.addWidget("org.kde.plasma.systemtray")
 panel.addWidget("org.kde.plasma.digitalclock")
 panel.addWidget("org.kde.plasma.showdesktop")