diff --git a/remote/components/Marionette.sys.mjs b/remote/components/Marionette.sys.mjs
index 1c66af86d5bd..9832a5ef1367 100644
--- a/remote/components/Marionette.sys.mjs
+++ b/remote/components/Marionette.sys.mjs
@@ -51,9 +51,6 @@ class MarionetteParentProcess {
     this.server = null;
     this._activePortPath;
 
-    this.classID = Components.ID("{786a1369-dca5-4adc-8486-33d23c88010a}");
-    this.helpInfo = "  --marionette       Enable remote control server.\n";
-
     // Initially set the enabled state based on the environment variable.
     this.enabled = Services.env.exists(ENV_ENABLED);
 
@@ -274,27 +271,25 @@ class MarionetteParentProcess {
     }
   }
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI([
-      "nsICommandLineHandler",
-      "nsIMarionette",
-      "nsIObserver",
-    ]);
-  }
+  // XPCOM
+
+  helpInfo = "  --marionette       Enable remote control server.\n";
+
+  QueryInterface = ChromeUtils.generateQI([
+    "nsICommandLineHandler",
+    "nsIMarionette",
+    "nsIObserver",
+  ]);
 }
 
 class MarionetteContentProcess {
-  constructor() {
-    this.classID = Components.ID("{786a1369-dca5-4adc-8486-33d23c88010a}");
-  }
-
   get running() {
     return Services.cpmm.sharedData.get(SHARED_DATA_ACTIVE_KEY) ?? false;
   }
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI(["nsIMarionette"]);
-  }
+  // XPCOM
+
+  QueryInterface = ChromeUtils.generateQI(["nsIMarionette"]);
 }
 
 export var Marionette;
diff --git a/remote/components/RemoteAgent.sys.mjs b/remote/components/RemoteAgent.sys.mjs
index f04953e8caaa..bbacf5526111 100644
--- a/remote/components/RemoteAgent.sys.mjs
+++ b/remote/components/RemoteAgent.sys.mjs
@@ -46,7 +46,6 @@ class RemoteAgentParentProcess {
   #allowOrigins;
   #allowSystemAccess;
   #browserStartupFinished;
-  #classID;
   #enabled;
   #host;
   #port;
@@ -60,7 +59,6 @@ class RemoteAgentParentProcess {
     this.#allowOrigins = null;
     this.#allowSystemAccess = Services.env.exists(ENV_ALLOW_SYSTEM_ACCESS);
     this.#browserStartupFinished = lazy.Deferred();
-    this.#classID = Components.ID("{8f685a9d-8181-46d6-a71d-869289099c6d}");
     this.#enabled = false;
 
     // Configuration for httpd.js
@@ -543,12 +541,7 @@ class RemoteAgentParentProcess {
 
   // XPCOM
 
-  get classID() {
-    return this.#classID;
-  }
-
-  get helpInfo() {
-    return `  --remote-debugging-port [<port>] Start the Firefox Remote Agent,
+  helpInfo = `  --remote-debugging-port [<port>] Start the Firefox Remote Agent,
                      which is a low-level remote debugging interface used for WebDriver
                      BiDi and CDP. Defaults to port 9222.
   --remote-allow-hosts <hosts> Values of the Host header to allow for incoming requests.
@@ -556,15 +549,12 @@ class RemoteAgentParentProcess {
   --remote-allow-origins <origins> Values of the Origin header to allow for incoming requests.
                      Please read security guidelines at https://firefox-source-docs.mozilla.org/remote/Security.html
   --remote-allow-system-access Enable privileged access to the application's parent process\n`;
-  }
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI([
-      "nsICommandLineHandler",
-      "nsIObserver",
-      "nsIRemoteAgent",
-    ]);
-  }
+  QueryInterface = ChromeUtils.generateQI([
+    "nsICommandLineHandler",
+    "nsIObserver",
+    "nsIRemoteAgent",
+  ]);
 }
 
 class RemoteAgentContentProcess {
@@ -572,9 +562,9 @@ class RemoteAgentContentProcess {
     return Services.cpmm.sharedData.get(SHARED_DATA_ACTIVE_KEY) ?? false;
   }
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI(["nsIRemoteAgent"]);
-  }
+  // XPCOM
+
+  QueryInterface = ChromeUtils.generateQI(["nsIRemoteAgent"]);
 }
 
 export var RemoteAgent;
diff --git a/remote/shared/Navigate.sys.mjs b/remote/shared/Navigate.sys.mjs
index ea5225dd86ba..988094071455 100644
--- a/remote/shared/Navigate.sys.mjs
+++ b/remote/shared/Navigate.sys.mjs
@@ -538,10 +538,10 @@ export class ProgressListener {
     return `[object ${this.constructor.name}]`;
   }
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI([
-      "nsIWebProgressListener",
-      "nsISupportsWeakReference",
-    ]);
-  }
+  // XPCOM
+
+  QueryInterface = ChromeUtils.generateQI([
+    "nsIWebProgressListener",
+    "nsISupportsWeakReference",
+  ]);
 }
diff --git a/remote/shared/listeners/ConsoleListener.sys.mjs b/remote/shared/listeners/ConsoleListener.sys.mjs
index 0344cf2be219..585a826ec98b 100644
--- a/remote/shared/listeners/ConsoleListener.sys.mjs
+++ b/remote/shared/listeners/ConsoleListener.sys.mjs
@@ -148,7 +148,7 @@ export class ConsoleListener {
     });
   };
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI(["nsIConsoleListener"]);
-  }
+  // XPCOM
+
+  QueryInterface = ChromeUtils.generateQI(["nsIConsoleListener"]);
 }
diff --git a/remote/shared/test/xpcshell/test_Navigate.js b/remote/shared/test/xpcshell/test_Navigate.js
index e34c628d38ee..a06cefb9995b 100644
--- a/remote/shared/test/xpcshell/test_Navigate.js
+++ b/remote/shared/test/xpcshell/test_Navigate.js
@@ -33,9 +33,7 @@ class MockRequest {
     this.originalURI = uri;
   }
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI(["nsIRequest", "nsIChannel"]);
-  }
+  QueryInterface = ChromeUtils.generateQI(["nsIRequest", "nsIChannel"]);
 }
 
 class MockWebProgress {
diff --git a/remote/shared/webdriver/Session.sys.mjs b/remote/shared/webdriver/Session.sys.mjs
index 1c1aadca5557..f41458d05bbf 100644
--- a/remote/shared/webdriver/Session.sys.mjs
+++ b/remote/shared/webdriver/Session.sys.mjs
@@ -443,9 +443,7 @@ export class WebDriverSession {
 
   // XPCOM
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI(["nsIHttpRequestHandler"]);
-  }
+  QueryInterface = ChromeUtils.generateQI(["nsIHttpRequestHandler"]);
 }
 
 /**
diff --git a/remote/webdriver-bidi/NewSessionHandler.sys.mjs b/remote/webdriver-bidi/NewSessionHandler.sys.mjs
index 342419033f72..e73d56552a96 100644
--- a/remote/webdriver-bidi/NewSessionHandler.sys.mjs
+++ b/remote/webdriver-bidi/NewSessionHandler.sys.mjs
@@ -51,7 +51,5 @@ export class WebDriverNewSessionHandler {
 
   // XPCOM
 
-  get QueryInterface() {
-    return ChromeUtils.generateQI(["nsIHttpRequestHandler"]);
-  }
+  QueryInterface = ChromeUtils.generateQI(["nsIHttpRequestHandler"]);
 }