diff --git a/lib/relation-definition.js b/lib/relation-definition.js
index 38f5552c..e3e369fe 100644
--- a/lib/relation-definition.js
+++ b/lib/relation-definition.js
@@ -114,7 +114,7 @@ function RelationDefinition(definition) {
   }
   this.modelThrough = definition.modelThrough;
   this.keyThrough = definition.keyThrough;
-  this.multiple = (this.type !== 'belongsTo' && this.type !== 'hasOne');
+  this.multiple = definition.multiple;
   this.properties = definition.properties || {};
   this.options = definition.options || {};
   this.scope = definition.scope;
@@ -1139,6 +1139,7 @@ RelationDefinition.belongsTo = function (modelFrom, modelTo, params) {
     keyFrom: fk,
     keyTo: idName,
     modelTo: modelTo,
+    multiple: false,
     properties: params.properties,
     scope: params.scope,
     options: params.options,
@@ -1447,6 +1448,7 @@ RelationDefinition.hasOne = function (modelFrom, modelTo, params) {
     keyFrom: pk,
     keyTo: fk,
     modelTo: modelTo,
+    multiple: false,
     properties: params.properties,
     scope: params.scope,
     options: params.options,