diff --git a/Assets/ROSBridgeLib/std_msgs/HeaderMsg.cs b/Assets/ROSBridgeLib/std_msgs/HeaderMsg.cs
index 7795f8b..5dd2745 100644
--- a/Assets/ROSBridgeLib/std_msgs/HeaderMsg.cs
+++ b/Assets/ROSBridgeLib/std_msgs/HeaderMsg.cs
@@ -55,7 +55,7 @@ public override string ToString() {
 			}
 			
 			public override string ToYAMLString() {
-				return "{\"seq\" : " + _seq + ", \"stamp\" : " + _stamp.ToYAMLString () + ", frame_id=" + _frame_id + "}";
+				return "{\"seq\" : " + _seq + ", \"stamp\" : " + _stamp.ToYAMLString () + ", \"frame_id\" : \"" + _frame_id +"\"}";
 			}
 		}
 	}