diff --git a/win/gatuna-client/TunnelLink.cs b/win/gatuna-client/TunnelLink.cs
index 12b3dfa..4880303 100644
--- a/win/gatuna-client/TunnelLink.cs
+++ b/win/gatuna-client/TunnelLink.cs
@@ -50,6 +50,11 @@ sealed class TunnelLink : IDisposable
         var et = (ushort)(data[12] << 8 | data[13]);
         if (et != Proto.EtherType)
             return;
+        // Skip our own outgoing frames (Npcap loops them back in promiscuous mode).
+        if (data[6] == _ourMac[0] && data[7] == _ourMac[1]
+            && data[8] == _ourMac[2] && data[9] == _ourMac[3]
+            && data[10] == _ourMac[4] && data[11] == _ourMac[5])
+            return;
         var srcMac = new byte[6];
         Buffer.BlockCopy(data, 6, srcMac, 0, 6);
         var payload = data.AsSpan(Proto.EthHeaderLen);