diff --git a/addons/web_editor/static/src/js/common/browser_extensions.js b/addons/web_editor/static/src/js/common/browser_extensions.js
new file mode 100644
index 00000000000..9a477529bcf
--- /dev/null
+++ b/addons/web_editor/static/src/js/common/browser_extensions.js
@@ -0,0 +1,21 @@
+/** @odoo-module **/
+
+// Redefine the getRangeAt function in order to avoid an error appearing
+// sometimes when an input element is focused on Firefox.
+// The error happens because the range returned by getRangeAt is "restricted".
+// Ex: Range { commonAncestorContainer: Restricted, startContainer: Restricted,
+// startOffset: 0, endContainer: Restricted, endOffset: 0, collapsed: true }
+// The solution consists in detecting when the range is restricted and then
+// redefining it manually based on the current selection.
+const originalGetRangeAt = Selection.prototype.getRangeAt;
+Selection.prototype.getRangeAt = function () {
+    let range = originalGetRangeAt.apply(this, arguments);
+    // Check if the range is restricted
+    if (range.startContainer && !Object.getPrototypeOf(range.startContainer)) {
+        // Define the range manually based on the selection
+        range = document.createRange();
+        range.setStart(this.anchorNode, 0);
+        range.setEnd(this.focusNode, 0);
+    }
+    return range;
+};