diff --git a/src/tsg_rule.cpp b/src/tsg_rule.cpp
index 6caca7c..ceafc0d 100644
--- a/src/tsg_rule.cpp
+++ b/src/tsg_rule.cpp
@@ -84,7 +84,7 @@ static int proto_str2id(tsg_protocol_t proto)
 		case	PROTO_UDP: return 101;
 		case	PROTO_HTTP: return 106;
 		case	PROTO_MAIL:	return 110;
-		case	PROTO_IMAP:	return 111;
+		case	PROTO_IMAP:	return 151;
 		case	PROTO_POP3: return 116;//116
 		case	PROTO_SMTP: return 122;//122
 		case	PROTO_DNS: return 103;