diff --git a/stm-firmware/main.c b/stm-firmware/main.c
index b83c501..36b3b4c 100644
--- a/stm-firmware/main.c
+++ b/stm-firmware/main.c
@@ -74,6 +74,9 @@ static inline void uart_gpio_config(void)
 	SHELL_UART_PORT->MODER |= ALTFUNC(SHELL_UART_RX_PIN) | ALTFUNC(SHELL_UART_TX_PIN);
 	SETAF(SHELL_UART_PORT, SHELL_UART_RX_PIN, SHELL_UART_RX_PIN_ALTFUNC);
 	SETAF(SHELL_UART_PORT, SHELL_UART_TX_PIN, SHELL_UART_TX_PIN_ALTFUNC);
+
+	/* Setup Pullup resistor at UART RX */
+	SHELL_UART_PORT->PUPDR |= PULLUP(SHELL_UART_RX_PIN);
 #endif
 }