diff --git a/browser/extensions/formautofill/test/browser/head.js b/browser/extensions/formautofill/test/browser/head.js
index 8de8488f1f7a..31c8d138b1e9 100644
--- a/browser/extensions/formautofill/test/browser/head.js
+++ b/browser/extensions/formautofill/test/browser/head.js
@@ -595,7 +595,7 @@ function waitPopupStateInChild(bc, messageName) {
 async function openPopupOn(browser, selector) {
   let childNotifiedPromise = waitPopupStateInChild(
     browser,
-    "FormAutoComplete:PopupOpened"
+    "AutoComplete:PopupOpened"
   );
   await SimpleTest.promiseFocus(browser);
 
@@ -613,7 +613,7 @@ async function openPopupOn(browser, selector) {
 async function openPopupOnSubframe(browser, frameBrowsingContext, selector) {
   let childNotifiedPromise = waitPopupStateInChild(
     frameBrowsingContext,
-    "FormAutoComplete:PopupOpened"
+    "AutoComplete:PopupOpened"
   );
 
   await SimpleTest.promiseFocus(browser);
@@ -637,7 +637,7 @@ async function closePopup(browser) {
 
   let childNotifiedPromise = waitPopupStateInChild(
     browser,
-    "FormAutoComplete:PopupClosed"
+    "AutoComplete:PopupClosed"
   );
   let popupClosePromise = BrowserTestUtils.waitForPopupEvent(
     browser.autoCompletePopup,
@@ -655,7 +655,7 @@ async function closePopup(browser) {
 async function closePopupForSubframe(browser, frameBrowsingContext) {
   let childNotifiedPromise = waitPopupStateInChild(
     browser,
-    "FormAutoComplete:PopupClosed"
+    "AutoComplete:PopupClosed"
   );
 
   let popupClosePromise = BrowserTestUtils.waitForPopupEvent(
diff --git a/toolkit/actors/AutoCompleteChild.sys.mjs b/toolkit/actors/AutoCompleteChild.sys.mjs
index 4cd9b9f3de97..3694e497d5c7 100644
--- a/toolkit/actors/AutoCompleteChild.sys.mjs
+++ b/toolkit/actors/AutoCompleteChild.sys.mjs
@@ -33,7 +33,7 @@ export class AutoCompleteChild extends JSWindowActorChild {
 
   receiveMessage(message) {
     switch (message.name) {
-      case "FormAutoComplete:HandleEnter": {
+      case "AutoComplete:HandleEnter": {
         this.selectedIndex = message.data.selectedIndex;
 
         let controller = Cc[
@@ -43,22 +43,22 @@ export class AutoCompleteChild extends JSWindowActorChild {
         break;
       }
 
-      case "FormAutoComplete:PopupClosed": {
+      case "AutoComplete:PopupClosed": {
         this._popupOpen = false;
         this.notifyListeners(message.name, message.data);
         break;
       }
 
-      case "FormAutoComplete:PopupOpened": {
+      case "AutoComplete:PopupOpened": {
         this._popupOpen = true;
         this.notifyListeners(message.name, message.data);
         break;
       }
 
-      case "FormAutoComplete:Focus": {
+      case "AutoComplete:Focus": {
         // XXX See bug 1582722
         // Before bug 1573836, the messages here didn't match
-        // ("FormAutoComplete:Focus" versus "FormAutoComplete:RequestFocus")
+        // ("AutoComplete:Focus" versus "AutoComplete:RequestFocus")
         // so this was never called. However this._input is actually a
         // nsIAutoCompleteInput, which doesn't have a focus() method, so it
         // wouldn't have worked anyway. So for now, I have just disabled this.
@@ -87,7 +87,7 @@ export class AutoCompleteChild extends JSWindowActorChild {
   }
 
   set selectedIndex(index) {
-    this.sendAsyncMessage("FormAutoComplete:SetSelectedIndex", { index });
+    this.sendAsyncMessage("AutoComplete:SetSelectedIndex", { index });
   }
 
   get selectedIndex() {
@@ -98,7 +98,7 @@ export class AutoCompleteChild extends JSWindowActorChild {
     // selectedIndex is trivial to catch (e.g. moving the mouse over the
     // list).
     let selectedIndexResult = Services.cpmm.sendSyncMessage(
-      "FormAutoComplete:GetSelectedIndex",
+      "AutoComplete:GetSelectedIndex",
       {
         browsingContext: this.browsingContext,
       }
@@ -131,7 +131,7 @@ export class AutoCompleteChild extends JSWindowActorChild {
     );
     let inputElementIdentifier = lazy.ContentDOMReference.get(element);
 
-    this.sendAsyncMessage("FormAutoComplete:MaybeOpenPopup", {
+    this.sendAsyncMessage("AutoComplete:MaybeOpenPopup", {
       results,
       rect,
       dir,
@@ -148,18 +148,18 @@ export class AutoCompleteChild extends JSWindowActorChild {
     // up in a state where the content thinks that a popup
     // is open when it isn't (or soon won't be).
     this._popupOpen = false;
-    this.sendAsyncMessage("FormAutoComplete:ClosePopup", {});
+    this.sendAsyncMessage("AutoComplete:ClosePopup", {});
   }
 
   invalidate() {
     if (this._popupOpen) {
       let results = this.getResultsFromController(this._input);
-      this.sendAsyncMessage("FormAutoComplete:Invalidate", { results });
+      this.sendAsyncMessage("AutoComplete:Invalidate", { results });
     }
   }
 
   selectBy(reverse, page) {
-    Services.cpmm.sendSyncMessage("FormAutoComplete:SelectBy", {
+    Services.cpmm.sendSyncMessage("AutoComplete:SelectBy", {
       browsingContext: this.browsingContext,
       reverse,
       page,
diff --git a/toolkit/actors/AutoCompleteParent.sys.mjs b/toolkit/actors/AutoCompleteParent.sys.mjs
index 611677a84f35..7e3e9be9c000 100644
--- a/toolkit/actors/AutoCompleteParent.sys.mjs
+++ b/toolkit/actors/AutoCompleteParent.sys.mjs
@@ -41,21 +41,18 @@ function compareContext(message) {
 // The browsingContext within the message data is either the one that has
 // the active autocomplete popup or the top-level of the one that has
 // the active autocomplete popup.
-Services.ppmm.addMessageListener(
-  "FormAutoComplete:GetSelectedIndex",
-  message => {
-    if (compareContext(message)) {
-      let actor = currentActor;
-      if (actor && actor.openedPopup) {
-        return actor.openedPopup.selectedIndex;
-      }
+Services.ppmm.addMessageListener("AutoComplete:GetSelectedIndex", message => {
+  if (compareContext(message)) {
+    let actor = currentActor;
+    if (actor && actor.openedPopup) {
+      return actor.openedPopup.selectedIndex;
     }
-
-    return -1;
   }
-);
 
-Services.ppmm.addMessageListener("FormAutoComplete:SelectBy", message => {
+  return -1;
+});
+
+Services.ppmm.addMessageListener("AutoComplete:SelectBy", message => {
   if (compareContext(message)) {
     let actor = currentActor;
     if (actor && actor.openedPopup) {
@@ -174,7 +171,7 @@ export class AutoCompleteParent extends JSWindowActorParent {
   handleEvent(evt) {
     switch (evt.type) {
       case "popupshowing": {
-        this.sendAsyncMessage("FormAutoComplete:PopupOpened", {});
+        this.sendAsyncMessage("AutoComplete:PopupOpened", {});
         break;
       }
 
@@ -188,7 +185,7 @@ export class AutoCompleteParent extends JSWindowActorParent {
           selectedIndex != -1
             ? AutoCompleteResultView.getStyleAt(selectedIndex)
             : "";
-        this.sendAsyncMessage("FormAutoComplete:PopupClosed", {
+        this.sendAsyncMessage("AutoComplete:PopupClosed", {
           selectedRowComment,
           selectedRowStyle,
         });
@@ -397,7 +394,7 @@ export class AutoCompleteParent extends JSWindowActorParent {
     }
 
     switch (message.name) {
-      case "FormAutoComplete:SetSelectedIndex": {
+      case "AutoComplete:SetSelectedIndex": {
         let { index } = message.data;
         if (this.openedPopup) {
           this.openedPopup.selectedIndex = index;
@@ -405,7 +402,7 @@ export class AutoCompleteParent extends JSWindowActorParent {
         break;
       }
 
-      case "FormAutoComplete:MaybeOpenPopup": {
+      case "AutoComplete:MaybeOpenPopup": {
         let { results, rect, dir, inputElementIdentifier, formOrigin } =
           message.data;
         if (lazy.DELEGATE_AUTOCOMPLETE) {
@@ -422,13 +419,13 @@ export class AutoCompleteParent extends JSWindowActorParent {
         break;
       }
 
-      case "FormAutoComplete:Invalidate": {
+      case "AutoComplete:Invalidate": {
         let { results } = message.data;
         this.invalidate(results);
         break;
       }
 
-      case "FormAutoComplete:ClosePopup": {
+      case "AutoComplete:ClosePopup": {
         if (lazy.DELEGATE_AUTOCOMPLETE) {
           lazy.GeckoViewAutocomplete.delegateDismiss();
           break;
@@ -489,7 +486,7 @@ export class AutoCompleteParent extends JSWindowActorParent {
    */
   handleEnter(aIsPopupSelection) {
     if (this.openedPopup) {
-      this.sendAsyncMessage("FormAutoComplete:HandleEnter", {
+      this.sendAsyncMessage("AutoComplete:HandleEnter", {
         selectedIndex: this.openedPopup.selectedIndex,
         isPopupSelection: aIsPopupSelection,
       });
@@ -507,7 +504,7 @@ export class AutoCompleteParent extends JSWindowActorParent {
     // disabled.
     /*
     if (this.openedPopup) {
-      this.sendAsyncMessage("FormAutoComplete:Focus");
+      this.sendAsyncMessage("AutoComplete:Focus");
     }
     */
   }
diff --git a/toolkit/components/formautofill/FormAutofillChild.sys.mjs b/toolkit/components/formautofill/FormAutofillChild.sys.mjs
index 8678a7bd45b8..026a25ec23c5 100644
--- a/toolkit/components/formautofill/FormAutofillChild.sys.mjs
+++ b/toolkit/components/formautofill/FormAutofillChild.sys.mjs
@@ -140,7 +140,7 @@ export class FormAutofillChild extends JSWindowActorChild {
     const { chromeEventHandler } = docShell;
 
     switch (messageName) {
-      case "FormAutoComplete:PopupClosed": {
+      case "AutoComplete:PopupClosed": {
         this.onPopupClosed(data.selectedRowStyle);
         Services.tm.dispatchToMainThread(() => {
           chromeEventHandler.removeEventListener("keydown", this, true);
@@ -148,7 +148,7 @@ export class FormAutofillChild extends JSWindowActorChild {
 
         break;
       }
-      case "FormAutoComplete:PopupOpened": {
+      case "AutoComplete:PopupOpened": {
         this.onPopupOpened();
         chromeEventHandler.addEventListener("keydown", this, true);
         break;
diff --git a/toolkit/modules/ActorManagerParent.sys.mjs b/toolkit/modules/ActorManagerParent.sys.mjs
index 5b31421ec631..46d69514752d 100644
--- a/toolkit/modules/ActorManagerParent.sys.mjs
+++ b/toolkit/modules/ActorManagerParent.sys.mjs
@@ -127,8 +127,8 @@ let JSWINDOWACTORS = {
       esModuleURI: "resource://gre/actors/AutoCompleteParent.sys.mjs",
       // These two messages are also used, but are currently synchronous calls
       // through the per-process message manager.
-      // "FormAutoComplete:GetSelectedIndex",
-      // "FormAutoComplete:SelectBy"
+      // "AutoComplete:GetSelectedIndex",
+      // "AutoComplete:SelectBy"
     },
 
     child: {