diff --git a/libraries/AP_HAL_Linux/UARTDriver.cpp b/libraries/AP_HAL_Linux/UARTDriver.cpp
index cc6cc87479..410824dcd2 100644
--- a/libraries/AP_HAL_Linux/UARTDriver.cpp
+++ b/libraries/AP_HAL_Linux/UARTDriver.cpp
@@ -131,16 +131,6 @@ void LinuxUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
         }
     }
 
-    // we have enough memory to have a larger transmit buffer for
-    // all ports. This means we don't get delays while waiting to
-    // write GPS config packets
-    if (rxS < 1024) {
-        rxS = 8192;
-    }            
-    if (txS < 8192) {
-        txS = 8192;
-    }
-    
     _initialised = false;
     while (_in_timer) hal.scheduler->delay(1);
 
@@ -158,6 +148,23 @@ void LinuxUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
         tcsetattr(_rd_fd, TCSANOW, &t);
     }
 
+    _allocate_buffers(rxS, txS);
+}
+
+void LinuxUARTDriver::_allocate_buffers(uint16_t rxS, uint16_t txS)
+{
+    /* we have enough memory to have a larger transmit buffer for
+     * all ports. This means we don't get delays while waiting to
+     * write GPS config packets
+     */
+
+    if (rxS < 8192) {
+        rxS = 8192;
+    }
+    if (txS < 8192) {
+        txS = 8192;
+    }
+
     /*
       allocate the read buffer
     */
diff --git a/libraries/AP_HAL_Linux/UARTDriver.h b/libraries/AP_HAL_Linux/UARTDriver.h
index 10acca7aa5..a9b6e21136 100644
--- a/libraries/AP_HAL_Linux/UARTDriver.h
+++ b/libraries/AP_HAL_Linux/UARTDriver.h
@@ -44,6 +44,7 @@ private:
     bool _packetise; // true if writes should try to be on mavlink boundaries
     enum flow_control _flow_control;
 
+    void _allocate_buffers(uint16_t rxS, uint16_t txS);
     void _tcp_start_connection(bool wait_for_connection);
     void _udp_start_connection(void);