diff --git a/dom/base/nsFrameMessageManager.cpp b/dom/base/nsFrameMessageManager.cpp
index 35c072fb7cc..eac1f9c76ea 100644
--- a/dom/base/nsFrameMessageManager.cpp
+++ b/dom/base/nsFrameMessageManager.cpp
@@ -1018,23 +1018,31 @@ nsFrameMessageManager::ReceiveMessage(nsISupports* aTarget,
                             aMessage.Length()));
       NS_ENSURE_TRUE(jsMessage, NS_ERROR_OUT_OF_MEMORY);
       JS::Rooted<JS::Value> syncv(cx, JS::BooleanValue(aIsSync));
-      JS_DefineProperty(cx, param, "target", targetv, JSPROP_ENUMERATE);
-      JS_DefineProperty(cx, param, "name", jsMessage, JSPROP_ENUMERATE);
-      JS_DefineProperty(cx, param, "sync", syncv, JSPROP_ENUMERATE);
-      JS_DefineProperty(cx, param, "json", json, JSPROP_ENUMERATE); // deprecated
-      JS_DefineProperty(cx, param, "data", json, JSPROP_ENUMERATE);
-      JS_DefineProperty(cx, param, "objects", cpowsv, JSPROP_ENUMERATE);
+      bool ok = JS_DefineProperty(cx, param, "target", targetv, JSPROP_ENUMERATE) &&
+                JS_DefineProperty(cx, param, "name", jsMessage, JSPROP_ENUMERATE) &&
+                JS_DefineProperty(cx, param, "sync", syncv, JSPROP_ENUMERATE) &&
+                JS_DefineProperty(cx, param, "json", json, JSPROP_ENUMERATE) && // deprecated
+                JS_DefineProperty(cx, param, "data", json, JSPROP_ENUMERATE) &&
+                JS_DefineProperty(cx, param, "objects", cpowsv, JSPROP_ENUMERATE);
+      NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
 
       // message.principal == null
       if (!aPrincipal) {
-        JS_DefineProperty(cx, param, "principal", JS::UndefinedHandleValue, JSPROP_ENUMERATE);
+        bool ok = JS_DefineProperty(cx, param, "principal",
+                                    JS::UndefinedHandleValue, JSPROP_ENUMERATE);
+        NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
       }
 
       // message.principal = the principal
       else {
         JS::Rooted<JS::Value> principalValue(cx);
-        rv = nsContentUtils::WrapNative(cx, aPrincipal, &NS_GET_IID(nsIPrincipal), &principalValue);
-        JS_DefineProperty(cx, param, "principal", principalValue, JSPROP_ENUMERATE);
+        nsresult rv = nsContentUtils::WrapNative(cx, aPrincipal,
+                                                 &NS_GET_IID(nsIPrincipal),
+                                                 &principalValue);
+        NS_ENSURE_SUCCESS(rv, rv);
+        bool ok = JS_DefineProperty(cx, param, "principal", principalValue,
+                                    JSPROP_ENUMERATE);
+        NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
       }
 
       JS::Rooted<JS::Value> thisValue(cx, JS::UndefinedValue());
@@ -1058,8 +1066,9 @@ nsFrameMessageManager::ReceiveMessage(nsISupports* aTarget,
       } else {
         // If the listener is a JS object which has receiveMessage function:
         if (!JS_GetProperty(cx, object, "receiveMessage", &funval) ||
-            !funval.isObject())
+            !funval.isObject()) {
           return NS_ERROR_UNEXPECTED;
+        }
 
         // Check if the object is even callable.
         NS_ENSURE_STATE(JS::IsCallable(&funval.toObject()));