diff --git a/addons/gamification/static/src/js/crash_manager.js b/addons/gamification/static/src/js/crash_manager.js
index f655f06dec0..806132bc4cd 100644
--- a/addons/gamification/static/src/js/crash_manager.js
+++ b/addons/gamification/static/src/js/crash_manager.js
@@ -11,10 +11,9 @@ CrashManager.include({
      * @override
      */
     getMapTitle() {
-        return {
-            ...this._super(...arguments),
+        return Object.assign({}, this._super(...arguments), {
             karma_error: _lt("Karma Error"),
-        };
+        });
     },
 });
 });
diff --git a/addons/web/static/src/js/public/public_crash_manager.js b/addons/web/static/src/js/public/public_crash_manager.js
index a352340db7a..8eae270f23a 100644
--- a/addons/web/static/src/js/public/public_crash_manager.js
+++ b/addons/web/static/src/js/public/public_crash_manager.js
@@ -14,12 +14,11 @@ const PublicCrashManager = CrashManager.extend({
      * @override
      */
     _displayWarning(message, title, options) {
-        this.displayNotification({
-            ...options,
+        this.displayNotification(Object.assign({}, options, {
             title,
             message,
             sticky: true,
-        });
+        }));
     },
 });
 
diff --git a/addons/web/static/src/js/services/crash_manager.js b/addons/web/static/src/js/services/crash_manager.js
index e08f87c8fcb..a430dfa8ef3 100644
--- a/addons/web/static/src/js/services/crash_manager.js
+++ b/addons/web/static/src/js/services/crash_manager.js
@@ -317,10 +317,9 @@ var CrashManager = AbstractService.extend({
      * @param {Object} options
      */
     _displayWarning: function (message, title, options) {
-        return new WarningDialog(this, {
-            ...options,
+        return new WarningDialog(this, Object.assign({}, options, {
             title,
-        }, {
+        }), {
             message,
         }).open();
     },