diff --git a/Config.h b/Config.h
index 2f41693..842d5df 100644
--- a/Config.h
+++ b/Config.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/SerialPort.cpp b/SerialPort.cpp
index e155220..1d5ff50 100644
--- a/SerialPort.cpp
+++ b/SerialPort.cpp
@@ -78,7 +78,9 @@ const uint8_t MMDVM_DEBUG5       = 0xF5U;
 
 const uint8_t PROTOCOL_VERSION   = 1U;
 
+#if defined(ENABLE_UDID)
 char UDID[] = "00000000000000000000000000000000";
+#endif
 
 CSerialPort::CSerialPort() :
 m_buffer(),
@@ -211,9 +213,11 @@ void CSerialPort::getVersion()
   for (uint8_t i = 0U; HARDWARE[i] != 0x00U; i++, count++)
     reply[count] = HARDWARE[i];
 
+#if defined(ENABLE_UDID)
   reply[count++] = '\0';
   for (uint8_t i = 0U; UDID[i] != 0x00U; i++, count++)
     reply[count] = UDID[i];
+#endif
 
   reply[1U] = count;
 
diff --git a/SerialSTM.cpp b/SerialSTM.cpp
index 3977878..61c20d3 100644
--- a/SerialSTM.cpp
+++ b/SerialSTM.cpp
@@ -433,13 +433,16 @@ void WriteUSART2(const uint8_t* data, uint16_t length)
 #endif
 
 /////////////////////////////////////////////////////////////////
+#if defined(ENABLE_UDID)
 extern char UDID[];
 extern "C" {
   #include <stdio.h>
 }
+#endif
 
 void CSerialPort::beginInt(uint8_t n, int speed)
 {
+#if defined(ENABLE_UDID)
 #if defined(STM32F4XX)
   uint32_t *id0 =  (uint32_t *) (0x1FFF7A10);
   uint32_t *id1 =  (uint32_t *) (0x1FFF7A10 + 0x04);
@@ -458,6 +461,7 @@ void CSerialPort::beginInt(uint8_t n, int speed)
   uint32_t *id1 =  (uint32_t *) (0x1FFFF7E8 + 0x04);
   uint32_t *id2 =  (uint32_t *) (0x1FFFF7E8 + 0x08);
   ::sprintf(UDID, "%04X%04X%08X%08X", *id00, *id01, *(unsigned int *)id1, *(unsigned int *)id2);
+#endif
 #endif
 
   switch (n) {
diff --git a/configs/D2RG_MMDVM_HS.h b/configs/D2RG_MMDVM_HS.h
index abde186..9c55cf2 100644
--- a/configs/D2RG_MMDVM_HS.h
+++ b/configs/D2RG_MMDVM_HS.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/configs/MMDVM_HS_Dual_Hat-12mhz.h b/configs/MMDVM_HS_Dual_Hat-12mhz.h
index df6d0d9..88779ef 100644
--- a/configs/MMDVM_HS_Dual_Hat-12mhz.h
+++ b/configs/MMDVM_HS_Dual_Hat-12mhz.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/MMDVM_HS_Dual_Hat.h b/configs/MMDVM_HS_Dual_Hat.h
index 64e600d..ace2477 100644
--- a/configs/MMDVM_HS_Dual_Hat.h
+++ b/configs/MMDVM_HS_Dual_Hat.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/MMDVM_HS_Hat-12mhz.h b/configs/MMDVM_HS_Hat-12mhz.h
index 56ad528..34d38f2 100644
--- a/configs/MMDVM_HS_Hat-12mhz.h
+++ b/configs/MMDVM_HS_Hat-12mhz.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/MMDVM_HS_Hat.h b/configs/MMDVM_HS_Hat.h
index a847690..643a817 100644
--- a/configs/MMDVM_HS_Hat.h
+++ b/configs/MMDVM_HS_Hat.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/NanoDV_NPI.h b/configs/NanoDV_NPI.h
index 50bb008..8f987d7 100644
--- a/configs/NanoDV_NPI.h
+++ b/configs/NanoDV_NPI.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/NanoDV_USB.h b/configs/NanoDV_USB.h
index eab6287..ce20034 100644
--- a/configs/NanoDV_USB.h
+++ b/configs/NanoDV_USB.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/configs/Nano_hotSPOT.h b/configs/Nano_hotSPOT.h
index 55d93e2..187cab6 100644
--- a/configs/Nano_hotSPOT.h
+++ b/configs/Nano_hotSPOT.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/ZUMspot_Libre.h b/configs/ZUMspot_Libre.h
index 2f41693..842d5df 100644
--- a/configs/ZUMspot_Libre.h
+++ b/configs/ZUMspot_Libre.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/configs/ZUMspot_RPi.h b/configs/ZUMspot_RPi.h
index 653a0e5..f7cd5f6 100644
--- a/configs/ZUMspot_RPi.h
+++ b/configs/ZUMspot_RPi.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/ZUMspot_USB.h b/configs/ZUMspot_USB.h
index 59b926c..b055bfb 100644
--- a/configs/ZUMspot_USB.h
+++ b/configs/ZUMspot_USB.h
@@ -107,4 +107,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/configs/ZUMspot_dualband.h b/configs/ZUMspot_dualband.h
index f21c673..d974f08 100644
--- a/configs/ZUMspot_dualband.h
+++ b/configs/ZUMspot_dualband.h
@@ -106,4 +106,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/ZUMspot_duplex.h b/configs/ZUMspot_duplex.h
index e90676f..80da2c5 100644
--- a/configs/ZUMspot_duplex.h
+++ b/configs/ZUMspot_duplex.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/configs/generic_duplex_gpio.h b/configs/generic_duplex_gpio.h
index 172ec76..96428b9 100644
--- a/configs/generic_duplex_gpio.h
+++ b/configs/generic_duplex_gpio.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif
diff --git a/configs/generic_duplex_usb.h b/configs/generic_duplex_usb.h
index 1a5a05d..b1e7b74 100644
--- a/configs/generic_duplex_usb.h
+++ b/configs/generic_duplex_usb.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+// #define ENABLE_UDID
+
 #endif
diff --git a/configs/generic_gpio.h b/configs/generic_gpio.h
index 9d95d06..e946f12 100644
--- a/configs/generic_gpio.h
+++ b/configs/generic_gpio.h
@@ -108,4 +108,7 @@
 // Disable frequency restrictions (satellite, ISS, etc)
 // #define DISABLE_FREQ_BAN
 
+// Enable UDID feature
+#define ENABLE_UDID
+
 #endif