diff --git a/src/mesh/Router.cpp b/src/mesh/Router.cpp
index 5cf8bfa7d..05f47d7f4 100644
--- a/src/mesh/Router.cpp
+++ b/src/mesh/Router.cpp
@@ -479,6 +479,11 @@ DecodeState perhapsDecode(meshtastic_MeshPacket *p)
                     LOG_ERROR("Invalid protobufs in received mesh packet id=0x%08x (bad psk?)!", p->id);
                 } else if (decodedtmp.portnum == meshtastic_PortNum_UNKNOWN_APP) {
                     LOG_ERROR("Invalid portnum (bad psk?)!");
+#if !(MESHTASTIC_EXCLUDE_PKI)
+                } else if (!owner.is_licensed && isToUs(p) && decodedtmp.portnum == meshtastic_PortNum_TEXT_MESSAGE_APP) {
+                    LOG_WARN("Rejecting legacy DM");
+                    return DecodeState::DECODE_FAILURE;
+#endif
                 } else {
                     p->decoded = decodedtmp;
                     p->which_payload_variant = meshtastic_MeshPacket_decoded_tag; // change type to decoded