diff --git a/libraries/AP_HAL_Linux/Util.cpp b/libraries/AP_HAL_Linux/Util.cpp
index 5492fc99ee..0312af3109 100644
--- a/libraries/AP_HAL_Linux/Util.cpp
+++ b/libraries/AP_HAL_Linux/Util.cpp
@@ -150,7 +150,7 @@ bool Util::get_system_id_unformatted(uint8_t buf[], uint8_t &len)
   as get_system_id_unformatted will already be ascii, we use the same
   ID here
  */
-bool Util::get_system_id(char buf[40])
+bool Util::get_system_id(char buf[50])
 {
     uint8_t len = 40;
     return get_system_id_unformatted((uint8_t *)buf, len);
diff --git a/libraries/AP_HAL_Linux/Util.h b/libraries/AP_HAL_Linux/Util.h
index 98b6440d19..8cf83dc49f 100644
--- a/libraries/AP_HAL_Linux/Util.h
+++ b/libraries/AP_HAL_Linux/Util.h
@@ -69,7 +69,7 @@ public:
 
     uint32_t available_memory(void) override;
 
-    bool get_system_id(char buf[40]) override;
+    bool get_system_id(char buf[50]) override;
     bool get_system_id_unformatted(uint8_t buf[], uint8_t &len) override;
 
 #ifdef ENABLE_HEAP