diff --git a/source/simulation2/serialization/BinarySerializer.cpp b/source/simulation2/serialization/BinarySerializer.cpp
index 467b991bba..7e88bf20e6 100644
--- a/source/simulation2/serialization/BinarySerializer.cpp
+++ b/source/simulation2/serialization/BinarySerializer.cpp
@@ -230,6 +230,8 @@ void CBinarySerializerScriptImpl::HandleScriptVal(JS::HandleValue val)
 				m_Serializer.Bool("value", b);
 				break;
 			}
+			// TODO: Follow upstream progresses about a JS::IsMapObject
+			// https://bugzilla.mozilla.org/show_bug.cgi?id=1285909
 			else if (protokey == JSProto_Map)
 			{
 				m_Serializer.NumberU8_Unbounded("type", SCRIPT_TYPE_OBJECT_MAP);
@@ -264,6 +266,8 @@ void CBinarySerializerScriptImpl::HandleScriptVal(JS::HandleValue val)
 				}
 				break;
 			}
+			// TODO: Follow upstream progresses about a JS::IsSetObject
+			// https://bugzilla.mozilla.org/show_bug.cgi?id=1285909
 			else if (protokey == JSProto_Set)
 			{
 				// TODO: When updating SpiderMonkey to a release after 38 use the C++ API for Sets.
diff --git a/source/simulation2/serialization/StdDeserializer.cpp b/source/simulation2/serialization/StdDeserializer.cpp
index 9262442759..6a0c9258ff 100644
--- a/source/simulation2/serialization/StdDeserializer.cpp
+++ b/source/simulation2/serialization/StdDeserializer.cpp
@@ -239,6 +239,7 @@ jsval CStdDeserializer::ReadScriptVal(const char* UNUSED(name), JS::HandleObject
 				JS::RootedValue propval(cx, ReadScriptVal("prop value", JS::NullPtr()));
 
 				utf16string prp(propname.begin(), propname.end());;
+// TODO: Should ask upstream about getting a variant of JS_SetProperty with a length param.
 				if (!JS_SetUCProperty(cx, obj, (const char16_t*)prp.data(), prp.length(), propval))
 					throw PSERROR_Deserialize_ScriptError();
 			}