diff --git a/addon/content/pEpForThunderbird.js b/addon/content/pEpForThunderbird.js
index c4db088..c4d8685 100644
--- a/addon/content/pEpForThunderbird.js
+++ b/addon/content/pEpForThunderbird.js
@@ -64,7 +64,7 @@ class pEpForThunderbird extends pEp {
     this.clientID = null;
     this.protectSubjects = true;
     this.isControllerAlert = false;
-    this.alertFolder = null;
+    this.alertArguments = null;
     this.passphrasePromptActive = false;
     this.pEpFolderCleanupTimer = null;
 
@@ -528,30 +528,46 @@ class pEpForThunderbird extends pEp {
         }
         this.msgQueueProcessing = false;
         this.log.debug(`Done processing queue, length is ${this.msgQueue.length}`);
-        if (hasEntries && this.isControllerAlert && this.alertFolder) {
+        if (hasEntries && this.isControllerAlert && this.alertArguments) {
           this.log.info("Launching alert window");
-          if (this.MOZ_APP_VERSION >= 88) {
-            Services.ww.openWindow(
-              null,
-              "chrome://messenger/content/newmailalert.xhtml",
-              "_blank",
-              "chrome,dialog=yes,titlebar=no,popup=yes",
-              this.alertFolder,
-            );
-          } else {
-            let folderArray = Cc["@mozilla.org/array;1"].createInstance(Ci.nsIMutableArray);
-            folderArray.appendElement(this.alertFolder);
-            Services.ww.openWindow(
-              null,
-              this.MOZ_APP_VERSION >= 73
-                ? "chrome://messenger/content/newmailalert.xhtml"
-                : "chrome://messenger/content/newmailalert.xul",
-              "_blank",
-              "chrome,dialog=yes,titlebar=no,popup=yes",
-              folderArray, null, false, 0,
-            );
+          // Copy the arguments to a new array in a generic fashion so we don't have to adjust every time
+          // Thunderbird changes this. Last change in https://bugzilla.mozilla.org/show_bug.cgi?id=1715713.
+          let args = Cc["@mozilla.org/array;1"].createInstance(Ci.nsIMutableArray);
+          for (let i = 0; i < this.alertArguments.length; i++) {
+            let v;
+            switch (this.alertArguments[i].constructor.name) {
+              case "Object":
+                args.appendElement(this.alertArguments[i]);
+                break;
+              case "Number":
+                v = Cc["@mozilla.org/supports-PRUint32;1"].createInstance(Ci.nsISupportsPRUint32);
+                v.data = this.alertArguments[i];
+                args.appendElement(v);
+                break;
+              case "Boolean":
+                v = Cc["@mozilla.org/supports-PRBool;1"].createInstance(Ci.nsISupportsPRBool);
+                v.data = this.alertArguments[i];
+                args.appendElement(v);
+                break;
+              case "String":
+                v = Cc["@mozilla.org/supports-string;1"].createInstance(Ci.nsISupportsString);
+                v.data = this.alertArguments[i];
+                args.appendElement(v);
+                break;
+              default:
+            }
           }
-          this.alertFolder = null;  // Done with this folder.
+
+          Services.ww.openWindow(
+            null,
+            this.MOZ_APP_VERSION >= 73
+              ? "chrome://messenger/content/newmailalert.xhtml"
+              : "chrome://messenger/content/newmailalert.xul",
+            "_blank",
+            "chrome,dialog=yes,titlebar=no,popup=yes",
+            args,
+          );
+          this.alertArguments = null;  // Done with these.
         }
       });
     }
diff --git a/addon/experiments.js b/addon/experiments.js
index 6f313c2..7ab203f 100644
--- a/addon/experiments.js
+++ b/addon/experiments.js
@@ -297,10 +297,10 @@ function paint(win) {
       pEpController.log.info(`Alert window was ${pEpController.isControllerAlert ? "" : "NOT "}lauched by the controller`);
       if (pEpController.isControllerAlert) {
         pEpController.isControllerAlert = false;
-        pEpController.alertFolder = null;
+        pEpController.alertArguments = null;
       } else {
         pEpController.isControllerAlert = true;
-        pEpController.alertFolder = win.arguments[0];
+        pEpController.alertArguments = win.arguments;
         win.onAlertLoad = () => null;
         win.close();
       }