diff --git a/src/d2m/converters/message-to-event.js b/src/d2m/converters/message-to-event.js
index 251ce90..f2720bd 100644
--- a/src/d2m/converters/message-to-event.js
+++ b/src/d2m/converters/message-to-event.js
@@ -176,7 +176,7 @@ async function attachmentToEvent(mentions, attachment) {
 			info: {
 				mimetype: attachment.content_type,
 				size: attachment.size,
-				duration: attachment.duration_secs ? attachment.duration_secs * 1000 : undefined
+				duration: attachment.duration_secs ? Math.round(attachment.duration_secs * 1000) : undefined
 			}
 		}
 	} else {