diff --git a/ipc/testshell/XPCShellEnvironment.cpp b/ipc/testshell/XPCShellEnvironment.cpp
index 367788f1af4..34892aad5af 100644
--- a/ipc/testshell/XPCShellEnvironment.cpp
+++ b/ipc/testshell/XPCShellEnvironment.cpp
@@ -657,7 +657,6 @@ XPCShellEnvironment::CreateEnvironment()
 
 XPCShellEnvironment::XPCShellEnvironment()
 :   mCx(NULL),
-    mJSPrincipals(NULL),
     mQuitting(JS_FALSE)
 {
 }
@@ -676,10 +675,6 @@ XPCShellEnvironment::~XPCShellEnvironment()
         JSRuntime *rt = JS_GetRuntime(mCx);
         JS_GC(rt);
 
-        if (mJSPrincipals) {
-            JS_DropPrincipals(rt, mJSPrincipals);
-        }
-
         JS_EndRequest(mCx);
         JS_DestroyContext(mCx);
 
@@ -749,10 +744,6 @@ XPCShellEnvironment::Init()
         rv = securityManager->GetSystemPrincipal(getter_AddRefs(principal));
         if (NS_FAILED(rv)) {
             fprintf(stderr, "+++ Failed to obtain SystemPrincipal from ScriptSecurityManager service.\n");
-        } else {
-            // fetch the JS principals and stick in a global
-            mJSPrincipals = nsJSPrincipals::get(principal);
-            JS_HoldPrincipals(mJSPrincipals);
         }
     } else {
         fprintf(stderr, "+++ Failed to get ScriptSecurityManager service, running without principals");
diff --git a/ipc/testshell/XPCShellEnvironment.h b/ipc/testshell/XPCShellEnvironment.h
index 43674bd5c70..61b586845e2 100644
--- a/ipc/testshell/XPCShellEnvironment.h
+++ b/ipc/testshell/XPCShellEnvironment.h
@@ -14,6 +14,8 @@
 #include "nsCOMPtr.h"
 #include "nsDebug.h"
 #include "nsStringGlue.h"
+#include "nsJSPrincipals.h"
+#include "nsContentUtils.h"
 
 struct JSContext;
 class JSObject;
@@ -34,7 +36,7 @@ public:
                         nsString* aResult = nullptr);
 
     JSPrincipals* GetPrincipal() {
-        return mJSPrincipals;
+        return nsJSPrincipals::get(nsContentUtils::GetSystemPrincipal());
     }
 
     JSObject* GetGlobalObject() {
@@ -59,7 +61,6 @@ protected:
 private:
     JSContext* mCx;
     nsAutoJSValHolder mGlobalHolder;
-    JSPrincipals* mJSPrincipals;
 
     JSBool mQuitting;
 };