diff --git a/src/kits/mail/MailAttachment.cpp b/src/kits/mail/MailAttachment.cpp
index ef3e2f31dd..5008039fdc 100644
--- a/src/kits/mail/MailAttachment.cpp
+++ b/src/kits/mail/MailAttachment.cpp
@@ -13,6 +13,7 @@
 #include <NodeInfo.h>
 
 #include <stdlib.h>
+#include <stdio.h>
 
 class _EXPORT BSimpleMailAttachment;
 class _EXPORT BAttributedMailAttachment;