diff --git a/How-to-upgrade-4G-extension-firmware.md b/How-to-upgrade-4G-extension-firmware.md
index 12aaef4..3c3c05c 100644
--- a/How-to-upgrade-4G-extension-firmware.md
+++ b/How-to-upgrade-4G-extension-firmware.md
@@ -227,7 +227,7 @@ echo -en  "AT+CGSN\r\n" |sudo socat - /dev/ttyUSB2,crnl
 OK
 ```
 ```
-echo -en  "AT+CIMI\r\n" |sudo socat - /dev/ttyUSB2,crn
+echo -en  "AT+CIMI\r\n" |sudo socat - /dev/ttyUSB2,crnl
 46001341620xxxx
 
 OK