diff --git a/content/base/src/nsScriptLoader.cpp b/content/base/src/nsScriptLoader.cpp
index f2d2163b1fc..e0a1cd6899b 100644
--- a/content/base/src/nsScriptLoader.cpp
+++ b/content/base/src/nsScriptLoader.cpp
@@ -22,6 +22,7 @@
 #include "nsIScriptRuntime.h"
 #include "nsIScriptSecurityManager.h"
 #include "nsIPrincipal.h"
+#include "nsJSPrincipals.h"
 #include "nsContentPolicyUtils.h"
 #include "nsIHttpChannel.h"
 #include "nsIHttpChannelInternal.h"
@@ -855,13 +856,14 @@ nsScriptLoader::EvaluateScript(nsScriptLoadRequest* aRequest,
   nsAutoCString url;
   nsContentUtils::GetWrapperSafeScriptFilename(mDocument, aRequest->mURI, url);
 
-  bool isUndefined;
-  rv = context->EvaluateString(aScript, globalObject->GetGlobalJSObject(),
-                               mDocument->NodePrincipal(),
-                               aRequest->mOriginPrincipal,
-                               url.get(), aRequest->mLineNo,
-                               JSVersion(aRequest->mJSVersion), nullptr,
-                               &isUndefined);
+  JS::CompileOptions options(context->GetNativeContext());
+  options.setFileAndLine(url.get(), aRequest->mLineNo)
+         .setVersion(JSVersion(aRequest->mJSVersion));
+  if (aRequest->mOriginPrincipal)
+    options.setOriginPrincipals(nsJSPrincipals::get(aRequest->mOriginPrincipal));
+  JS::Value ignored;
+  rv = context->EvaluateStringWithValue(aScript, *globalObject->GetGlobalJSObject(),
+                                        options, /* aCoerceToString = */ false, ignored);
 
   // Put the old script back in case it wants to do anything else.
   mCurrentScript = oldCurrent;
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 0b440eb154f..d63b46f3592 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -9748,11 +9748,12 @@ nsGlobalWindow::RunTimeoutHandler(nsTimeout* aTimeout,
     uint32_t lineNo = 0;
     handler->GetLocation(&filename, &lineNo);
 
-    bool is_undefined;
-    aScx->EvaluateString(nsDependentString(script), FastGetGlobalJSObject(),
-                         timeout->mPrincipal, timeout->mPrincipal,
-                         filename, lineNo, JSVERSION_DEFAULT, nullptr,
-                         &is_undefined);
+    JS::CompileOptions options(aScx->GetNativeContext());
+    options.setFileAndLine(filename, lineNo)
+           .setVersion(JSVERSION_DEFAULT);
+    JS::Value ignored;
+    aScx->EvaluateStringWithValue(nsDependentString(script), *FastGetGlobalJSObject(),
+                                  options, /*aCoerceToString = */ false, ignored);
   } else {
     nsCOMPtr<nsIVariant> dummy;
     nsCOMPtr<nsISupports> me(static_cast<nsIDOMWindow *>(this));
diff --git a/dom/src/jsurl/nsJSProtocolHandler.cpp b/dom/src/jsurl/nsJSProtocolHandler.cpp
index 03df7d307de..2bb81444267 100644
--- a/dom/src/jsurl/nsJSProtocolHandler.cpp
+++ b/dom/src/jsurl/nsJSProtocolHandler.cpp
@@ -255,11 +255,11 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel,
         useSandbox = !subsumes;
     }
 
-    nsString result;
-    bool isUndefined;
-
+    JS::Value v = JSVAL_VOID;
     // Finally, we have everything needed to evaluate the expression.
 
+    JSContext *cx = scriptContext->GetNativeContext();
+    JSAutoRequest ar(cx);
     if (useSandbox) {
         // We were asked to use a sandbox, or the channel owner isn't allowed
         // to execute in this context.  Evaluate the javascript URL in a
@@ -268,9 +268,6 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel,
 
         // First check to make sure it's OK to evaluate this script to
         // start with.  For example, script could be disabled.
-        JSContext *cx = scriptContext->GetNativeContext();
-        JSAutoRequest ar(cx);
-
         bool ok;
         rv = securityManager->CanExecuteScripts(cx, principal, &ok);
         if (NS_FAILED(rv)) {
@@ -301,8 +298,6 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel,
         rv = xpc->HoldObject(cx, sandboxObj, getter_AddRefs(sandbox));
         NS_ENSURE_SUCCESS(rv, rv);
 
-        jsval rval = JSVAL_VOID;
-
         // Push our JSContext on the context stack so the JS_ValueToString call (and
         // JS_ReportPendingException, if relevant) will use the principal of cx.
         // Note that we do this as late as possible to make popping simpler.
@@ -316,42 +311,26 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel,
         }
 
         rv = xpc->EvalInSandboxObject(NS_ConvertUTF8toUTF16(script), cx,
-                                      sandbox, true, &rval);
+                                      sandbox, true, &v);
 
         // Propagate and report exceptions that happened in the
         // sandbox.
         if (JS_IsExceptionPending(cx)) {
             JS_ReportPendingException(cx);
-            isUndefined = true;
-        } else {
-            isUndefined = rval == JSVAL_VOID;
-        }
-
-        if (!isUndefined && NS_SUCCEEDED(rv)) {
-            NS_ASSERTION(JSVAL_IS_STRING(rval), "evalInSandbox is broken");
-
-            nsDependentJSString depStr;
-            if (!depStr.init(cx, JSVAL_TO_STRING(rval))) {
-                JS_ReportPendingException(cx);
-                isUndefined = true;
-            } else {
-                result = depStr;
-            }
         }
 
         stack->Pop(nullptr);
     } else {
         // No need to use the sandbox, evaluate the script directly in
         // the given scope.
-        rv = scriptContext->EvaluateString(NS_ConvertUTF8toUTF16(script),
-                                           globalJSObject, // obj
-                                           principal,
-                                           principal,
-                                           mURL.get(),     // url
-                                           1,              // line no
-                                           JSVERSION_DEFAULT,
-                                           &result,
-                                           &isUndefined);
+        JS::CompileOptions options(cx);
+        options.setFileAndLine(mURL.get(), 1)
+               .setVersion(JSVERSION_DEFAULT);
+        rv = scriptContext->EvaluateStringWithValue(NS_ConvertUTF8toUTF16(script),
+                                                    *globalJSObject,
+                                                    options,
+                                                    /* aCoerceToString = */ true,
+                                                    v);
 
         // If there's an error on cx as a result of that call, report
         // it now -- either we're just running under the event loop,
@@ -360,18 +339,21 @@ nsresult nsJSThunk::EvaluateScript(nsIChannel *aChannel,
         // lose the error), or it might be JS that then proceeds to
         // cause an error of its own (which will also make us lose
         // this error).
-        JSContext *cx = scriptContext->GetNativeContext();
-        JSAutoRequest ar(cx);
         ::JS_ReportPendingException(cx);
     }
-    
+
     if (NS_FAILED(rv)) {
         rv = NS_ERROR_MALFORMED_URI;
     }
-    else if (isUndefined) {
+    else if (v.isUndefined()) {
         rv = NS_ERROR_DOM_RETVAL_UNDEFINED;
     }
     else {
+        nsDependentJSString result;
+        if (!result.init(cx, JSVAL_TO_STRING(v))) {
+            return NS_ERROR_OUT_OF_MEMORY;
+        }
+
         char *bytes;
         uint32_t bytesLen;
         NS_NAMED_LITERAL_CSTRING(isoCharset, "ISO-8859-1");