diff --git a/src/knx/cemi_frame.cpp b/src/knx/cemi_frame.cpp
index 289e83a..c4d6ff1 100644
--- a/src/knx/cemi_frame.cpp
+++ b/src/knx/cemi_frame.cpp
@@ -160,6 +160,8 @@ void CemiFrame::fillTelegramTP(uint8_t* data)
     data[len - 1] = calcCrcTP(data, len - 1);
 }
 
+#ifdef USE_RF
+
 uint16_t CemiFrame::telegramLengthtRF() const
 {
     return totalLenght() - 3;
@@ -183,7 +185,7 @@ void CemiFrame::fillTelegramRF(uint8_t* data)
 
     //printHex("cEMI_fill: ", &data[0], len);
 }
-
+#endif
 uint8_t* CemiFrame::data()
 {
     return _data;
@@ -315,7 +317,7 @@ void CemiFrame::destinationAddress(uint16_t value)
 {
     pushWord(value, _ctrl1 + 4);
 }
-
+#ifdef USE_RF
 uint8_t* CemiFrame::rfSerialOrDoA() const
 {
     return _rfSerialOrDoA;
@@ -345,7 +347,7 @@ void CemiFrame::rfLfn(uint8_t rfLfn)
 {
     _rfLfn = rfLfn;
 }
-
+#endif
 NPDU& CemiFrame::npdu()
 {
     return _npdu;
diff --git a/src/knx/cemi_frame.h b/src/knx/cemi_frame.h
index d9db230..ef30165 100644
--- a/src/knx/cemi_frame.h
+++ b/src/knx/cemi_frame.h
@@ -5,6 +5,7 @@
 #include "npdu.h"
 #include "tpdu.h"
 #include "apdu.h"
+#include "config.h"
 
 #define NPDU_LPDU_DIFF 8
 #define TPDU_NPDU_DIFF 1
@@ -56,6 +57,7 @@ class CemiFrame
     uint16_t destinationAddress() const;
     void destinationAddress(uint16_t value);
 
+#ifdef USE_RF
     // only for RF medium
     uint8_t* rfSerialOrDoA() const;
     void rfSerialOrDoA(uint8_t* rfSerialOrDoA);
@@ -63,7 +65,7 @@ class CemiFrame
     void rfInfo(uint8_t rfInfo);
     uint8_t rfLfn() const;
     void rfLfn(uint8_t rfInfo);
-
+#endif
     NPDU& npdu();
     TPDU& tpdu();
     APDU& apdu();
@@ -80,8 +82,11 @@ class CemiFrame
     APDU _apdu;
     uint16_t _length = 0; // only set if created from byte array
 
+#ifdef USE_RF
+    // FIXME: integrate this propery in _data
     // only for RF medium
     uint8_t* _rfSerialOrDoA = 0;
     uint8_t  _rfInfo = 0;
     uint8_t  _rfLfn = 0xFF; // RF Data Link layer frame number
+ #endif
 };
\ No newline at end of file