diff --git a/ESP-IDF_Robot/tutorial/docs/source/transmitter.rst b/ESP-IDF_Robot/tutorial/docs/source/transmitter.rst
index 934369611..b55c7bcd2 100644
--- a/ESP-IDF_Robot/tutorial/docs/source/transmitter.rst
+++ b/ESP-IDF_Robot/tutorial/docs/source/transmitter.rst
@@ -9,7 +9,7 @@ Configuration Variables
     uint8_t receiver_mac[ESP_NOW_ETH_ALEN]  = {0xe4, 0xb0, 0x63, 0x17, 0x9e, 0x44};
 
 Sending & Ecapsulating Data
-------------------------------
+----------------------------
 
 .. code-block:: c