diff --git a/src/main/java/eu/siacs/conversations/generator/IqGenerator.java b/src/main/java/eu/siacs/conversations/generator/IqGenerator.java
index 835b9bf6c..42c57b24f 100644
--- a/src/main/java/eu/siacs/conversations/generator/IqGenerator.java
+++ b/src/main/java/eu/siacs/conversations/generator/IqGenerator.java
@@ -262,7 +262,7 @@ public class IqGenerator extends AbstractGenerator {
 		request.addChild("filename").setContent(file.getName());
 		request.addChild("size").setContent(String.valueOf(file.getExpectedSize()));
 		if (mime != null) {
-			request.addChild("content-type", mime);
+			request.addChild("content-type").setContent(mime);
 		}
 		return packet;
 	}