diff --git a/src/wifi/model/wifi-phy.cc b/src/wifi/model/wifi-phy.cc
index 0d064a4d0..9415ec8d4 100644
--- a/src/wifi/model/wifi-phy.cc
+++ b/src/wifi/model/wifi-phy.cc
@@ -2781,7 +2781,8 @@ WifiPhy::StartReceivePreamble (Ptr<Packet> packet, double rxPowerW, Time rxDurat
           NS_FATAL_ERROR ("Received OFDM 802.11 signal with no SIG field");
           return;
         }
-      txVector.SetChannelWidth (GetChannelWidth ());
+      uint16_t channelWidth = GetChannelWidth ();
+      txVector.SetChannelWidth (channelWidth > 20 ? 20 : channelWidth);
       for (uint8_t i = 0; i < GetNModes (); i++)
         {
           WifiMode mode = GetMode (i);