diff --git a/radio/src/cli.cpp b/radio/src/cli.cpp
index b3ac3ad13..f17ee83bf 100644
--- a/radio/src/cli.cpp
+++ b/radio/src/cli.cpp
@@ -37,8 +37,9 @@
 #include "opentx.h"
 #include <ctype.h>
 
-#define CLI_STACK_SIZE    500
-#define CLI_MAX_ARGS      8
+#define CLI_STACK_SIZE                 500
+#define CLI_COMMAND_MAX_ARGS           8
+#define CLI_COMMAND_MAX_LEN            256
 
 extern Fifo<512> uart3TxFifo;
 OS_TID cliTaskId;
@@ -253,14 +254,14 @@ int cliExecCommand(const char ** argv)
 int cliExecLine(char * line)
 {
   int len = strlen(line);
-  const char * argv[CLI_MAX_ARGS];
+  const char * argv[CLI_COMMAND_MAX_ARGS];
   memset(argv, 0, sizeof(argv));
   int argc = 1;
   argv[0] = line;
   for (int i=0; i<len; i++) {
     if (line[i] == ' ') {
       line[i] = '\0';
-      if (argc < CLI_MAX_ARGS) {
+      if (argc < CLI_COMMAND_MAX_ARGS) {
         argv[argc++] = &line[i+1];
       }
     }
@@ -270,7 +271,7 @@ int cliExecLine(char * line)
 
 void cliTask(void * pdata)
 {
-  char line[256];
+  char line[CLI_COMMAND_MAX_LEN+1];
   uint8_t pos = 0;
 
   cliPrompt();
@@ -302,7 +303,7 @@ void cliTask(void * pdata)
       pos = 0;
       cliPrompt();
     }
-    else if (isascii(c)) {
+    else if (isascii(c) && pos < CLI_COMMAND_MAX_LEN) {
       line[pos++] = c;
       serialPutc(c);
     }
diff --git a/radio/src/main_arm.cpp b/radio/src/main_arm.cpp
index d841b5a12..66b217ca3 100644
--- a/radio/src/main_arm.cpp
+++ b/radio/src/main_arm.cpp
@@ -51,8 +51,8 @@ void handleCli()
 
   while(cliRxFifo.pop(c)) {
     //send back
-    sendUsbSerialChar(c);
-    sendUsbSerialChar('+');
+    usbSerialPutc(c);
+    usbSerialPutc('+');
   }
 
 }
diff --git a/radio/src/serial.cpp b/radio/src/serial.cpp
index e589c8185..e64e0ec6d 100644
--- a/radio/src/serial.cpp
+++ b/radio/src/serial.cpp
@@ -44,7 +44,7 @@
 void serialPutc(char c)
 {
 #if defined(USB_SERIAL)
-  sendUsbSerialChar(c);
+  usbSerialPutc(c);
 #else
   serial2Putc(c);
 #endif
diff --git a/radio/src/targets/taranis/board_taranis.h b/radio/src/targets/taranis/board_taranis.h
index 30f3b5fe9..1ab9c1410 100644
--- a/radio/src/targets/taranis/board_taranis.h
+++ b/radio/src/targets/taranis/board_taranis.h
@@ -283,6 +283,7 @@ void backlightInit(void);
 int usbPlugged(void);
 void usbInit(void);
 void usbDeInit(void);
+void usbSerialPutc(uint8_t c);
 
 #if defined(__cplusplus) && !defined(SIMU)
 }
diff --git a/radio/src/targets/taranis/usbd_cdc.cpp b/radio/src/targets/taranis/usbd_cdc.cpp
index 56d4c5e7f..7e742b7cd 100644
--- a/radio/src/targets/taranis/usbd_cdc.cpp
+++ b/radio/src/targets/taranis/usbd_cdc.cpp
@@ -157,7 +157,7 @@ static uint16_t VCP_Ctrl (uint32_t Cmd, uint8_t* Buf, uint32_t Len)
 uint16_t usbWraps = 0;
 uint16_t charsWritten = 0;
 
-void sendUsbSerialChar(uint8_t c)
+void usbSerialPutc(uint8_t c)
 {
   if (!cdcConnected) return;