diff --git a/src/bpid/csn.cpp b/src/bpid/csn.cpp
index ce84a18..ea967e2 100644
--- a/src/bpid/csn.cpp
+++ b/src/bpid/csn.cpp
@@ -13,6 +13,9 @@
 namespace arduino { namespace csn {
 
     bool get(uint8_t *in, uint32_t size) {
+#if defined ARDUINO_UNOR4_WIFI
+    return false;
+#else
         if (size < CRYPTO_SN_SIZE) {
             return false;
         }
@@ -21,6 +24,7 @@ namespace arduino { namespace csn {
             return false;
         }
         return true;
+#endif
     }
 
 }} // arduino::csn
diff --git a/src/bpid/mac.h b/src/bpid/mac.h
index 169f54e..ecf3c2c 100644
--- a/src/bpid/mac.h
+++ b/src/bpid/mac.h
@@ -23,7 +23,7 @@
     #define IFACE_MAC_ADDR_LENGTH WL_MAC_ADDR_LENGTH
 #elif defined(ARDUINO_UNOR4_WIFI)
     #include <WiFi.h>
-    #define IFACE_MAC_ADDR_LENGTH WL_MAC_ADDR_LENGTH
+    #define IFACE_MAC_ADDR_LENGTH 6
 #elif defined(ARDUINO_OPTA)
     #include <Ethernet.h>
     #define IFACE_MAC_ADDR_LENGTH 6