diff --git a/.eslintignore b/.eslintignore
index a3f5ffae1543..b1ed7dff30e9 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -136,7 +136,6 @@ dom/workers/test/threadErrors_worker1.js
 intl/l10n/
 
 # Exclude everything but self-hosted JS
-js/ductwork/
 js/examples/
 js/public/
 js/xpconnect/
diff --git a/.eslintrc-test-paths.js b/.eslintrc-test-paths.js
index 8f2b135328be..507b25167a9b 100644
--- a/.eslintrc-test-paths.js
+++ b/.eslintrc-test-paths.js
@@ -54,6 +54,7 @@ const extraXpcshellTestPaths = [
   "intl/benchmarks/",
   "intl/l10n/test/",
   "ipc/testshell/tests/",
+  "js/ductwork/debugger/tests/",
   "memory/replace/dmd/test/",
   "netwerk/test/httpserver/test/",
   "testing/modules/tests/xpcshell/",
diff --git a/js/ductwork/debugger/JSDebugger.cpp b/js/ductwork/debugger/JSDebugger.cpp
index 436ab1262e39..f0145ce19ea7 100644
--- a/js/ductwork/debugger/JSDebugger.cpp
+++ b/js/ductwork/debugger/JSDebugger.cpp
@@ -35,7 +35,7 @@ JSDebugger::AddClass(JS::Handle<JS::Value> global, JSContext* cx) {
     return NS_ERROR_INVALID_ARG;
   }
 
-  JS::RootedObject obj(cx, &global.toObject());
+  JS::Rooted<JSObject*> obj(cx, &global.toObject());
   obj = js::UncheckedUnwrap(obj, /* stopAtWindowProxy = */ false);
   if (!obj) {
     return NS_ERROR_FAILURE;
diff --git a/js/ductwork/debugger/jsdebugger.jsm b/js/ductwork/debugger/jsdebugger.jsm
index ed5e9f66f7b0..53be813286d4 100644
--- a/js/ductwork/debugger/jsdebugger.jsm
+++ b/js/ductwork/debugger/jsdebugger.jsm
@@ -3,7 +3,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-var EXPORTED_SYMBOLS = [ "addDebuggerToGlobal", "addSandboxedDebuggerToGlobal" ];
+"use strict";
+
+var EXPORTED_SYMBOLS = ["addDebuggerToGlobal", "addSandboxedDebuggerToGlobal"];
 
 /*
  * This is the js module for Debugger. Import it like so:
@@ -29,7 +31,7 @@ function addDebuggerToGlobal(global) {
 // Defines the Debugger in a sandbox global in a separate compartment. This
 // ensures the debugger and debuggee are in different compartments.
 function addSandboxedDebuggerToGlobal(global) {
-  var sb = Cu.Sandbox(global, {freshCompartment: true});
+  const sb = Cu.Sandbox(global, { freshCompartment: true });
   addDebuggerToGlobal(sb);
   global.Debugger = sb.Debugger;
 }
@@ -50,7 +52,7 @@ function initPromiseDebugging(global) {
   global.eval(polyfillSource);
 }
 
-let polyfillSource = `
+const polyfillSource = `
   Object.defineProperty(Debugger.Object.prototype, "promiseState", {
     get() {
       const state = this.PromiseDebugging.getState(this.unsafeDereference());
diff --git a/js/ductwork/debugger/tests/head_dbg.js b/js/ductwork/debugger/tests/head_dbg.js
index aad37f5f128c..48942bdb7a96 100644
--- a/js/ductwork/debugger/tests/head_dbg.js
+++ b/js/ductwork/debugger/tests/head_dbg.js
@@ -3,11 +3,12 @@
 
 "use strict";
 
-function testGlobal(aName) {
-  let systemPrincipal = Cc["@mozilla.org/systemprincipal;1"]
-    .createInstance(Ci.nsIPrincipal);
+function testGlobal(name) {
+  const systemPrincipal = Cc["@mozilla.org/systemprincipal;1"].createInstance(
+    Ci.nsIPrincipal
+  );
 
-  let sandbox = Cu.Sandbox(systemPrincipal);
-  Cu.evalInSandbox("this.__name = '" + aName + "'", sandbox);
+  const sandbox = Cu.Sandbox(systemPrincipal);
+  Cu.evalInSandbox("this.__name = '" + name + "'", sandbox);
   return sandbox;
 }
diff --git a/js/ductwork/debugger/tests/test_nativewrappers.js b/js/ductwork/debugger/tests/test_nativewrappers.js
index 3523121164d2..69af71822b80 100644
--- a/js/ductwork/debugger/tests/test_nativewrappers.js
+++ b/js/ductwork/debugger/tests/test_nativewrappers.js
@@ -1,6 +1,9 @@
-function run_test()
-{
-  const {addDebuggerToGlobal} = ChromeUtils.import("resource://gre/modules/jsdebugger.jsm");
+"use strict";
+
+function run_test() {
+  const { addDebuggerToGlobal } = ChromeUtils.import(
+    "resource://gre/modules/jsdebugger.jsm"
+  );
 
   Services.prefs.setBoolPref("security.allow_eval_with_system_principal", true);
   registerCleanupFunction(() => {
@@ -8,30 +11,35 @@ function run_test()
   });
 
   addDebuggerToGlobal(globalThis);
-  var g = testGlobal("test1");
+  const g = testGlobal("test1");
 
-  var dbg = new Debugger();
+  const dbg = new Debugger();
   dbg.addDebuggee(g);
-  dbg.onDebuggerStatement = function(aFrame) {
-    let args = aFrame["arguments"];
+  dbg.onDebuggerStatement = function(frame) {
+    const args = frame.arguments;
     try {
       args[0];
       Assert.ok(true);
-    } catch(ex) {
+    } catch (ex) {
       Assert.ok(false);
     }
   };
 
   g.eval("function stopMe(arg) {debugger;}");
 
-  g2 = testGlobal("test2");
+  const g2 = testGlobal("test2");
   g2.g = g;
-  g2.eval("(" + function createBadEvent() {
-    Cu.importGlobalProperties(["DOMParser"]);
-    let parser = new DOMParser();
-    let doc = parser.parseFromString("<foo></foo>", "text/xml");
-    g.stopMe(doc.createEvent("MouseEvent"));
-  } + ")()");
+  g2.eval(
+    "(" +
+      function createBadEvent() {
+        // eslint-disable-next-line mozilla/reject-importGlobalProperties
+        Cu.importGlobalProperties(["DOMParser"]);
+        const parser = new DOMParser();
+        const doc = parser.parseFromString("<foo></foo>", "text/xml");
+        g.stopMe(doc.createEvent("MouseEvent"));
+      } +
+      ")()"
+  );
 
   dbg.removeAllDebuggees();
 }