diff --git a/dom/ipc/tests/test_force_oop_iframe.html b/dom/ipc/tests/test_force_oop_iframe.html
index a133cf4f6832..a38fdea55f02 100644
--- a/dom/ipc/tests/test_force_oop_iframe.html
+++ b/dom/ipc/tests/test_force_oop_iframe.html
@@ -13,7 +13,9 @@
 
 add_task(async function() {
   await SpecialPowers.pushPrefEnv({"set": [["fission.oopif.attribute", true],
-                                           ["dom.ipc.processCount", 10000]]});
+                                           ["dom.ipc.processCount", 10000],
+                                           // Temporarily allow use of eval() in ChromeTask.js.
+                                           ["security.allow_eval_with_system_principal", true]]});
 
   // This iframe should be loaded out of process. Unfortunately as of the time
   // of this test's creation, many different events which we could use to detect
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index c219d146dcc0..f691683647db 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -2659,7 +2659,7 @@ pref("csp.overrule_about_uris_without_csp_whitelist", false);
 pref("csp.skip_about_page_has_csp_assert", false);
 // assertion flag will be set to false after fixing Bug 1473549
 pref("security.allow_eval_with_system_principal", false);
-pref("security.uris_using_eval_with_system_principal", "autocomplete.xml,redux.js,react-redux.js,content-task.js,preferencesbindings.js,lodash.js,jszip.js,sinon-7.2.7.js,ajv-4.1.1.js,setup,jsol.js,chrometask_chromescript,simpletest/simpletest.js");
+pref("security.uris_using_eval_with_system_principal", "autocomplete.xml,redux.js,react-redux.js,content-task.js,preferencesbindings.js,lodash.js,jszip.js,sinon-7.2.7.js,ajv-4.1.1.js,setup,jsol.js,simpletest/simpletest.js");
 #endif
 
 #if defined(DEBUG) || defined(FUZZING)