diff --git a/src/inet/UDPEndPointImplLwIP.cpp b/src/inet/UDPEndPointImplLwIP.cpp
index 62a2a5549e18ef..a81b3922492ce2 100644
--- a/src/inet/UDPEndPointImplLwIP.cpp
+++ b/src/inet/UDPEndPointImplLwIP.cpp
@@ -133,7 +133,7 @@ CHIP_ERROR UDPEndPointImplLwIP::LwIPBindInterface(struct udp_pcb * aUDP, Interfa
 InterfaceId UDPEndPointImplLwIP::GetBoundInterface() const
 {
 #if HAVE_LWIP_UDP_BIND_NETIF
-    return InterfaceId(netif_get_by_index(mUDP->netif_idx + 1));
+    return InterfaceId(netif_get_by_index(++(mUDP->netif_idx)));
 #else
     return InterfaceId(mUDP->intf_filter);
 #endif