diff --git a/lib/datasource.js b/lib/datasource.js
index ef0bd4e6..5e7bf66b 100644
--- a/lib/datasource.js
+++ b/lib/datasource.js
@@ -1816,9 +1816,14 @@ DataSource.prototype.defineForeignKey = function defineForeignKey(className, key
 
   var fkDef = {type: pkType};
   var foreignMeta = this.columnMetadata(foreignClassName, pkName);
-  if(foreignMeta && foreignMeta.dataType) {
+  if (foreignMeta && (foreignMeta.dataType || foreignMeta.dataLength)) {
     fkDef[this.connector.name] = {};
-    fkDef[this.connector.name].dataType = foreignMeta.dataType;
+    if (foreignMeta.dataType) {
+      fkDef[this.connector.name].dataType = foreignMeta.dataType;
+    }
+    if (foreignMeta.dataLength) {
+      fkDef[this.connector.name].dataLength = foreignMeta.dataLength;
+    }
   }
   if (this.connector.defineForeignKey) {
     var cb = function (err, keyType) {