diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 169e34677..a612b7329 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -30,6 +30,7 @@ New user-visible features
 Bugs fixed
 ----------
 - (wifi) #467 - WiFi: Failed association process
+- (wifi) #468 - WiFi: Wrong txDuration for trigger frame
 
 Release 3.35
 ============
diff --git a/src/wifi/model/he/he-frame-exchange-manager.cc b/src/wifi/model/he/he-frame-exchange-manager.cc
index c364e91c0..b0f6ec8f0 100644
--- a/src/wifi/model/he/he-frame-exchange-manager.cc
+++ b/src/wifi/model/he/he-frame-exchange-manager.cc
@@ -356,7 +356,8 @@ HeFrameExchangeManager::SendPsduMap (void)
               m_staExpectTbPpduFrom.insert (station.first);
             }
 
-          Time txDuration = m_phy->CalculateTxDuration (m_triggerFrame->GetSize (),
+          Ptr<WifiPsdu> triggerPsdu = GetWifiPsdu (m_triggerFrame, acknowledgment->muBarTxVector);
+          Time txDuration = m_phy->CalculateTxDuration (triggerPsdu->GetSize (),
                                                         acknowledgment->muBarTxVector,
                                                         m_phy->GetPhyBand ());
           // update acknowledgmentTime to correctly set the Duration/ID
@@ -372,7 +373,7 @@ HeFrameExchangeManager::SendPsduMap (void)
                          &m_staExpectTbPpduFrom, m_staExpectTbPpduFrom.size ());
           m_channelAccessManager->NotifyAckTimeoutStartNow (timeout);
 
-          ForwardMpduDown (m_triggerFrame, acknowledgment->muBarTxVector);
+          ForwardPsduDown (triggerPsdu, acknowledgment->muBarTxVector);
           return;
         }
     }
@@ -733,6 +734,11 @@ HeFrameExchangeManager::CalculateAcknowledgmentTime (WifiAcknowledgment* acknowl
                                                              txVector, m_phy->GetPhyBand ());
 
       uint32_t muBarSize = GetMuBarSize (dlMuTfMuBarAcknowledgment->barTypes);
+      if (dlMuTfMuBarAcknowledgment->muBarTxVector.GetModulationClass () >= WIFI_MOD_CLASS_VHT)
+        {
+          // MU-BAR TF will be sent as an S-MPDU
+          muBarSize = MpduAggregator::GetSizeIfAggregated (muBarSize, 0);
+        }
       dlMuTfMuBarAcknowledgment->acknowledgmentTime = m_phy->GetSifs ()
                                                       + m_phy->CalculateTxDuration (muBarSize,
                                                                                     dlMuTfMuBarAcknowledgment->muBarTxVector,
diff --git a/src/wifi/model/ht/ht-frame-exchange-manager.cc b/src/wifi/model/ht/ht-frame-exchange-manager.cc
index 20fb6a915..184d3f09c 100644
--- a/src/wifi/model/ht/ht-frame-exchange-manager.cc
+++ b/src/wifi/model/ht/ht-frame-exchange-manager.cc
@@ -431,7 +431,7 @@ HtFrameExchangeManager::SendMpduFromBaManager (Ptr<QosTxop> edca, Time available
 
   // we can transmit the BlockAckReq frame
   Ptr<const WifiMacQueueItem> mpdu = edca->GetBaManager ()->GetBar ();
-  SendPsduWithProtection (Create<WifiPsdu> (mpdu, false), txParams);
+  SendPsduWithProtection (GetWifiPsdu (Copy (mpdu), txParams.m_txVector), txParams);
   return true;
 }