diff --git a/scapy/layers/inet.py b/scapy/layers/inet.py
index e0836efce0085daf401cb245db116417794b274b..ed61c84d1b59b239b125f39d9e46767a6e789a6b 100644
--- a/scapy/layers/inet.py
+++ b/scapy/layers/inet.py
@@ -440,8 +440,8 @@ class TCP(Packet):
                     IntField("seq", 0),
                     IntField("ack", 0),
                     BitField("dataofs", None, 4),
-                    BitField("reserved", 0, 4),
-                    FlagsField("flags", 0x2, 8, "FSRPAUEC"),
+                    BitField("reserved", 0, 3),
+                    FlagsField("flags", 0x2, 9, "FSRPAUECN"),
                     ShortField("window", 8192),
                     XShortField("chksum", None),
                     ShortField("urgptr", 0),