diff --git a/lib/include.js b/lib/include.js
index b6cd5d5f..c27da09f 100644
--- a/lib/include.js
+++ b/lib/include.js
@@ -495,8 +495,10 @@ Inclusion.include = function (objects, include, options, cb) {
     function includeHasManySimple(callback) {
       //Map for Indexing objects by their id for faster retrieval
       var objIdMap2 = includeUtils.buildOneToOneIdentityMapWithOrigKeys(objs, relation.keyFrom);
-      // all ids of primary objects to use in query
-      var sourceIds = objIdMap2.originalKeys;//Object.keys(objIdMap);
+      console.log("### objIdMap2: " + JSON.stringify(objIdMap2));
+      // all ids of primary objects to use in query are original. So, ObjectIds stay ObjectIds and Ints stay Ints.
+      // No .toString() conversion.
+      var sourceIds = objIdMap2.originalKeys;
 
       filter.where[relation.keyTo] = {
         inq: uniq(sourceIds)
diff --git a/lib/include_utils.js b/lib/include_utils.js
index 52e1be0f..99919cd2 100644
--- a/lib/include_utils.js
+++ b/lib/include_utils.js
@@ -32,6 +32,14 @@ function buildOneToOneIdentityMap(objs, idName) {
 function newIdMap(origKeyField, valueField) {
   //var idMap = Object.create(null); // not any single properties within our identity map
   var idMap = {};
+  Object.defineProperty(idMap, "set", {
+    value: function(origKey, value){
+      var key = origKey.toString();
+      this[key] = {};
+      this[key][origKeyField] = origKey;
+      this[key][valueField] = value;
+    }
+  });
   Object.defineProperty(idMap, "keys", {    // can ask for keys simply by idMap.keys
     get: function(){ return Object.keys(this); },
     enumerable: false // explicitly non-enumerable
@@ -75,10 +83,7 @@ function buildOneToOneIdentityMapWithOrigKeys(objs, idName) {
   for(var i = 0; i < objs.length; i++) {
     var obj = objs[i];
     var id = obj[idName];
-    idMap[id.toString()] = {
-      originalKey: id,
-      value: obj
-    };
+    idMap.set(id, obj);
   }
   return idMap;
 }
@@ -103,6 +108,21 @@ function buildOneToManyIdentityMap(objs, idName) {
   return idMap;
 }
 
+function buildOneToManyIdentityMapWithOrigKeys(objs, idName) {
+  var idMap = newIdMap("originalKey", "value");
+  for(var i = 0; i < objs.length; i++) {
+    var obj = objs[i];
+    var id = obj[idName];
+    var idString = id.toString();
+    if(idString in idMap) {
+      idMap[idString]["value"].push(obj);
+    } else {
+      idMap.set(id, [obj]);
+    }
+  }
+  return idMap;
+}
+
 
 /**
  * Yeah, it joins. You need three things id -> obj1 map, id -> [obj2] map and merge function.