1 files changed, 2 insertions, 1 deletions
diff --git a/lib/mime.h b/lib/mime.h
index 0a05c2a..a64f41d 100644
--- a/lib/mime.h
+++ b/lib/mime.h
@@ -130,7 +130,8 @@ struct curl_mimepart {
   size_t lastreadstatus;           /* Last read callback returned status. */
 };
 
-CURLcode Curl_mime_add_header(struct curl_slist **slp, const char *fmt, ...);
+CURLcode Curl_mime_add_header(struct curl_slist **slp, const char *fmt, ...)
+  CURL_PRINTF(2, 3);
 
 #if !defined(CURL_DISABLE_MIME) && (!defined(CURL_DISABLE_HTTP) ||      \
                                     !defined(CURL_DISABLE_SMTP) ||      \