diff --git a/libraries/WiFiS3/src/WiFiClient.h b/libraries/WiFiS3/src/WiFiClient.h
index 972b98b8a..4917dab62 100644
--- a/libraries/WiFiS3/src/WiFiClient.h
+++ b/libraries/WiFiS3/src/WiFiClient.h
@@ -30,8 +30,6 @@
 #include "FifoBuffer.h"
 #include <memory>
 
-#define RX_BUFFER_DIM 1024
-
 class WiFiClient : public Client {
 
 public:
@@ -74,6 +72,7 @@ class WiFiClient : public Client {
   int _sock;
   int _connectionTimeout = 0;
   void getSocket();
+  static constexpr uint32_t RX_BUFFER_DIM = 1024;
   std::shared_ptr<FifoBuffer<uint8_t,RX_BUFFER_DIM>> rx_buffer;
   int _read();
   void read_if_needed(size_t s);
diff --git a/libraries/WiFiS3/src/WiFiUdp.h b/libraries/WiFiS3/src/WiFiUdp.h
index 8eda0ca65..a6d7c6026 100644
--- a/libraries/WiFiS3/src/WiFiUdp.h
+++ b/libraries/WiFiS3/src/WiFiUdp.h
@@ -30,11 +30,10 @@
 #include "Modem.h"
 #include "FifoBuffer.h"
 
-#define RX_BUFFER_DIM 1461
-
 class WiFiUDP : public UDP {
 private:
   int _sock; 
+  static constexpr uint32_t RX_BUFFER_DIM = 1461;
   FifoBuffer<uint8_t,RX_BUFFER_DIM> rx_buffer;
 
 protected: