diff --git a/devtools/server/tests/xpcshell/head_dbg.js b/devtools/server/tests/xpcshell/head_dbg.js
index 8c7d98a84239..a9b214569898 100644
--- a/devtools/server/tests/xpcshell/head_dbg.js
+++ b/devtools/server/tests/xpcshell/head_dbg.js
@@ -346,16 +346,8 @@ var listener = {
 
 Services.console.registerListener(listener);
 
-function testGlobal(name) {
-  const sandbox = Cu.Sandbox(
-    Cc["@mozilla.org/systemprincipal;1"].createInstance(Ci.nsIPrincipal)
-  );
-  sandbox.__name = name;
-  return sandbox;
-}
-
 function addTestGlobal(name, server = DevToolsServer) {
-  const global = testGlobal(name);
+  const global = createTestGlobal(name);
   server.addTestGlobal(global);
   return global;
 }
diff --git a/devtools/server/tests/xpcshell/test_getyoungestframe.js b/devtools/server/tests/xpcshell/test_getyoungestframe.js
index 9684211b5c9a..ec3b52524b77 100644
--- a/devtools/server/tests/xpcshell/test_getyoungestframe.js
+++ b/devtools/server/tests/xpcshell/test_getyoungestframe.js
@@ -11,7 +11,7 @@ function run_test() {
   const xpcInspector = Cc["@mozilla.org/jsinspector;1"].getService(
     Ci.nsIJSInspector
   );
-  const g = testGlobal("test1");
+  const g = createTestGlobal("test1");
 
   const dbg = makeDebugger();
   dbg.uncaughtExceptionHook = testExceptionHook;
diff --git a/devtools/server/tests/xpcshell/test_nativewrappers.js b/devtools/server/tests/xpcshell/test_nativewrappers.js
index 7e95a2283648..629b050e3264 100644
--- a/devtools/server/tests/xpcshell/test_nativewrappers.js
+++ b/devtools/server/tests/xpcshell/test_nativewrappers.js
@@ -8,7 +8,7 @@ function run_test() {
     "resource://gre/modules/jsdebugger.jsm"
   );
   addDebuggerToGlobal(this);
-  const g = testGlobal("test1");
+  const g = createTestGlobal("test1");
 
   const dbg = makeDebugger();
   dbg.addDebuggee(g);
@@ -24,7 +24,7 @@ function run_test() {
 
   g.eval("function stopMe(arg) {debugger;}");
 
-  const g2 = testGlobal("test2");
+  const g2 = createTestGlobal("test2");
   g2.g = g;
   // Not using the "stringify a function" trick because that runs afoul of the
   // Cu.importGlobalProperties lint and we don't need it here anyway.
diff --git a/devtools/server/tests/xpcshell/test_promises_run_to_completion.js b/devtools/server/tests/xpcshell/test_promises_run_to_completion.js
index 76711a61e152..4d1e8745fee0 100644
--- a/devtools/server/tests/xpcshell/test_promises_run_to_completion.js
+++ b/devtools/server/tests/xpcshell/test_promises_run_to_completion.js
@@ -36,7 +36,9 @@
 const Debugger = require("Debugger");
 
 function test_promises_run_to_completion() {
-  const g = testGlobal("test global for test_promises_run_to_completion.js");
+  const g = createTestGlobal(
+    "test global for test_promises_run_to_completion.js"
+  );
   const dbg = new Debugger(g);
   g.Assert = Assert;
   const log = [""];
diff --git a/devtools/server/tests/xpcshell/test_safe-getter.js b/devtools/server/tests/xpcshell/test_safe-getter.js
index 32aad6f9b835..06bbdd0781ff 100644
--- a/devtools/server/tests/xpcshell/test_safe-getter.js
+++ b/devtools/server/tests/xpcshell/test_safe-getter.js
@@ -8,7 +8,7 @@ function run_test() {
     "resource://gre/modules/jsdebugger.jsm"
   );
   addDebuggerToGlobal(this);
-  const g = testGlobal("test");
+  const g = createTestGlobal("test");
   const dbg = new Debugger();
   const gw = dbg.addDebuggee(g);