diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 54ca21876..1bdf161ab 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -43,6 +43,7 @@ Bugs fixed
 - Bug 2920 - wifi: Default MaxSlrc and fragmentation threshold values differ from standard
 - Bug 2924 - documentation about Peek/Dequeue usage
 - Bug 2925 - wifi: MinstrelHt provides strange results at low SNR with A-MPDU enabled
+- Bug 2931 - Queue Disc drops the CE marked packets
 
 Known issues
 ------------
diff --git a/src/internet/model/ipv4-queue-disc-item.cc b/src/internet/model/ipv4-queue-disc-item.cc
index 97d54de71..4b9d4828c 100644
--- a/src/internet/model/ipv4-queue-disc-item.cc
+++ b/src/internet/model/ipv4-queue-disc-item.cc
@@ -86,7 +86,7 @@ bool
 Ipv4QueueDiscItem::Mark (void)
 {
   NS_LOG_FUNCTION (this);
-  if (!m_headerAdded && (m_header.GetEcn () == Ipv4Header::ECN_ECT1 || m_header.GetEcn () == Ipv4Header::ECN_ECT0))
+  if (!m_headerAdded && m_header.GetEcn () != Ipv4Header::ECN_NotECT)
     {
       m_header.SetEcn (Ipv4Header::ECN_CE);
       return true;
diff --git a/src/internet/model/ipv6-queue-disc-item.cc b/src/internet/model/ipv6-queue-disc-item.cc
index 508fec462..3bc4cd9ff 100644
--- a/src/internet/model/ipv6-queue-disc-item.cc
+++ b/src/internet/model/ipv6-queue-disc-item.cc
@@ -86,7 +86,7 @@ bool
 Ipv6QueueDiscItem::Mark (void)
 {
   NS_LOG_FUNCTION (this);
-  if (!m_headerAdded && (m_header.GetEcn () == Ipv6Header::ECN_ECT1 || m_header.GetEcn () == Ipv6Header::ECN_ECT0))
+  if (!m_headerAdded && m_header.GetEcn () != Ipv6Header::ECN_NotECT)
     {
       m_header.SetEcn (Ipv6Header::ECN_CE);
       return true;