diff --git a/src/stm32/Kconfig b/src/stm32/Kconfig
index 2d1495c4..cdd4527f 100644
--- a/src/stm32/Kconfig
+++ b/src/stm32/Kconfig
@@ -233,18 +233,25 @@ choice
     config STM32_SERIAL_USART1_ALT_PA15_PA14
         bool "Serial (on USART1 PA15/PA14)" if LOW_LEVEL_OPTIONS && MACH_STM32F0
         select SERIAL
+    config STM32_SERIAL_USART1_ALT_PB7_PB6
+        bool "Serial (on USART1 PB7/PB6)" if LOW_LEVEL_OPTIONS && MACH_STM32F4
+        select SERIAL
     config STM32_SERIAL_USART2
         bool "Serial (on USART2 PA3/PA2)" if LOW_LEVEL_OPTIONS
         select SERIAL
     config STM32_SERIAL_USART2_ALT_PA15_PA14
         bool "Serial (on USART2 PA15/PA14)" if LOW_LEVEL_OPTIONS && MACH_STM32F0
         select SERIAL
+    config STM32_SERIAL_USART2_ALT_PD6_PD5
+        bool "Serial (on USART2 PD6/PD5)" if LOW_LEVEL_OPTIONS && MACH_STM32F4
+        select SERIAL
     config STM32_SERIAL_USART3
-        bool "Serial (on USART3 PB11/PB10)" if LOW_LEVEL_OPTIONS && !MACH_STM32F0
+        bool "Serial (on USART3 PB11/PB10)" if LOW_LEVEL_OPTIONS
+        depends on MACH_STM32F405 || MACH_STM32F407 || MACH_STM32F446
         select SERIAL
     config STM32_SERIAL_USART3_ALT_PD9_PD8
-        depends on LOW_LEVEL_OPTIONS && (MACH_STM32F405 || MACH_STM32F407)
-        bool "Serial (on USART3 PD9/PD8)"
+        bool "Serial (on USART3 PD9/PD8)" if LOW_LEVEL_OPTIONS
+        depends on MACH_STM32F405 || MACH_STM32F407 || MACH_STM32F446
         select SERIAL
     config STM32_CANBUS_PA11_PA12
         bool "CAN bus (on PA11/PA12)" if HAVE_STM32_CANBUS
diff --git a/src/stm32/serial.c b/src/stm32/serial.c
index 38432fa5..5806eaab 100644
--- a/src/stm32/serial.c
+++ b/src/stm32/serial.c
@@ -18,12 +18,24 @@
   #define GPIO_Tx GPIO('A', 9)
   #define USARTx USART1
   #define USARTx_IRQn USART1_IRQn
+#elif CONFIG_STM32_SERIAL_USART1_ALT_PB7_PB6
+  DECL_CONSTANT_STR("RESERVE_PINS_serial", "PB7,PB6");
+  #define GPIO_Rx GPIO('B', 7)
+  #define GPIO_Tx GPIO('B', 6)
+  #define USARTx USART1
+  #define USARTx_IRQn USART1_IRQn
 #elif CONFIG_STM32_SERIAL_USART2
   DECL_CONSTANT_STR("RESERVE_PINS_serial", "PA3,PA2");
   #define GPIO_Rx GPIO('A', 3)
   #define GPIO_Tx GPIO('A', 2)
   #define USARTx USART2
   #define USARTx_IRQn USART2_IRQn
+#elif CONFIG_STM32_SERIAL_USART2_ALT_PD6_PD5
+  DECL_CONSTANT_STR("RESERVE_PINS_serial", "PD6,PD5");
+  #define GPIO_Rx GPIO('D', 6)
+  #define GPIO_Tx GPIO('D', 5)
+  #define USARTx USART2
+  #define USARTx_IRQn USART2_IRQn
 #elif CONFIG_STM32_SERIAL_USART3
   DECL_CONSTANT_STR("RESERVE_PINS_serial", "PB11,PB10");
   #define GPIO_Rx GPIO('B', 11)