diff --git a/scripts/base/protocols/ftp/gridftp.bro b/scripts/base/protocols/ftp/gridftp.bro
index 68be66d53a..5090eebb3d 100644
--- a/scripts/base/protocols/ftp/gridftp.bro
+++ b/scripts/base/protocols/ftp/gridftp.bro
@@ -74,6 +74,8 @@ event ConnThreshold::bytes_threshold_crossed(c: connection, threshold: count, is
 	{
 	if ( threshold < size_threshold || "gridftp-data" in c$service || c$duration > max_time )
 		return;
+	if ( ! data_channel_initial_criteria(c) )
+		return;
 
 	add c$service["gridftp-data"];
 	event GridFTP::data_channel_detected(c);