diff --git a/backbone.js b/backbone.js
index 70d9a9ef7..1b11cbbf0 100644
--- a/backbone.js
+++ b/backbone.js
@@ -982,7 +982,7 @@
 
     // Ensure that we have the appropriate request data.
     if (!params.data && model && (method == 'create' || method == 'update')) {
-      params.contentType = 'application/json',
+      params.contentType = 'application/json';
       params.data = JSON.stringify(model.toJSON());
     }