diff --git a/lib/relation-definition.js b/lib/relation-definition.js
index c46b1c3a..bf7d3826 100644
--- a/lib/relation-definition.js
+++ b/lib/relation-definition.js
@@ -328,6 +328,19 @@ function lookupModel(models, modelName) {
   }
 }
 
+/*!
+ * Normalize polymorphic parameters
+ * @param {Object|String} params Name of the polymorphic relation or params
+ * @returns {Object} The normalized parameters
+ */
+function polymorphicParams(params) {
+  if (typeof params === 'string') params = { as: params };
+  if (typeof params.as !== 'string') params.as = 'reference'; // default
+  params.foreignKey = params.foreignKey || i8n.camelize(params.as + '_id', true);
+  params.discriminator = params.discriminator || i8n.camelize(params.as + '_type', true);
+  return params;
+};
+
 /**
  * Define a "one to many" relationship by specifying the model name
  * 
@@ -369,11 +382,11 @@ RelationDefinition.hasMany = function hasMany(modelFrom, modelTo, params) {
   var idName = modelFrom.dataSource.idName(modelFrom.modelName) || 'id';
   var discriminator;
   
-  if (typeof params.polymorphic === 'string') {
-    var polymorphic = params.polymorphic;
-    discriminator = i8n.camelize(polymorphic + '_type', true);
+  if (params.polymorphic) {
+    var polymorphic = polymorphicParams(params.polymorphic);
+    discriminator = polymorphic.discriminator;
     if (!params.invert) {
-      fk = i8n.camelize(polymorphic + '_id', true);
+      fk = polymorphic.foreignKey;
     }
     if (!params.through) {
       modelTo.dataSource.defineProperty(modelTo.modelName, discriminator, { type: 'string', index: true });
@@ -857,16 +870,22 @@ RelationDefinition.belongsTo = function (modelFrom, modelTo, params) {
   }
   
   if (params.polymorphic) {
-    var polymorphic = modelTo;
+    if (params.polymorphic === true) {
+      // modelTo will be the name of the polymorphic relation (string)
+      var polymorphic = polymorphicParams(modelTo);
+    } else {
+      var polymorphic = polymorphicParams(params.polymorphic);
+    }
+    
     modelTo = null; // will lookup dynamically
     
     var idName = params.idName || 'id';
-    var relationName = params.as || i8n.camelize(polymorphic, true);
-    var fk = i8n.camelize(polymorphic + '_id', true);
-    var discriminator = i8n.camelize(polymorphic + '_type', true);
+    var relationName = params.as || polymorphic.as;
+    var fk = polymorphic.foreignKey;
+    var discriminator = polymorphic.discriminator;
     
-    if (typeof params.idType === 'string') { // explicit key type
-      modelFrom.dataSource.defineProperty(modelFrom.modelName, fk, { type: params.idType, index: true });
+    if (typeof polymorphic.idType === 'string') { // explicit key type
+      modelFrom.dataSource.defineProperty(modelFrom.modelName, fk, { type: polymorphic.idType, index: true });
     } else { // try to use the same foreign key type as modelFrom
       modelFrom.dataSource.defineForeignKey(modelFrom.modelName, fk, modelFrom.modelName);
     }
diff --git a/test/relations.test.js b/test/relations.test.js
index a6580649..6809e43b 100644
--- a/test/relations.test.js
+++ b/test/relations.test.js
@@ -641,7 +641,10 @@ describe('relations', function () {
 
     it('can be declared', function (done) {
       Author.hasMany(Picture, { polymorphic: 'imageable' });
-      Reader.hasMany(Picture, { polymorphic: 'imageable' });
+      Reader.hasMany(Picture, { polymorphic: { // alt syntax
+        as: 'imageable', foreignKey: 'imageableId',
+        discriminator: 'imageableType'
+      } });
       Picture.belongsTo('imageable', { polymorphic: true });
       db.automigrate(done);
     });