diff --git a/Spine/SerializeOperation.swift b/Spine/SerializeOperation.swift
index 839c986b..6601fba2 100644
--- a/Spine/SerializeOperation.swift
+++ b/Spine/SerializeOperation.swift
@@ -91,8 +91,10 @@ class SerializeOperation: Operation {
 			}
 		}
 		
-		serializedData["attributes"] = attributes
-	}
+    if attributes.count > 0 {
+      serializedData["attributes"] = attributes
+    }
+  }
 
 	
 	// MARK: Relationships