diff --git a/src/main/java/de/mrbesen/telegram/MessageBuilder.java b/src/main/java/de/mrbesen/telegram/MessageBuilder.java
index 93de12c..92016e2 100644
--- a/src/main/java/de/mrbesen/telegram/MessageBuilder.java
+++ b/src/main/java/de/mrbesen/telegram/MessageBuilder.java
@@ -107,15 +107,20 @@ public class MessageBuilder {
 	}
 
 	public MessageBuilder setAttachment(Attachment type, String cont) {
+		if(cont == null) {
+			if(type != Attachment.none) throw new IllegalArgumentException("cont == null requires type == none");
+			attachmenttype = type;
+			attachment = null;
+			return this;
+		}
+
 		if(attachmenttype != Attachment.none) {
 			throw new IllegalArgumentException("You can only attach one thing!");
 		}
-		if(cont == null) {
-			throw new IllegalArgumentException("attachment empty!");
-		}
+
 		attachmenttype = type;
 		try {
-			attachment =  URLEncoder.encode(cont, "UTF-8");
+			attachment = URLEncoder.encode(cont, "UTF-8");
 		} catch (UnsupportedEncodingException e) {
 			e.printStackTrace();
 		}