diff --git a/boards/mro/ctrl-zero-classic/nuttx-config/include/board.h b/boards/mro/ctrl-zero-classic/nuttx-config/include/board.h
index 52206cccd00f..ea2147442699 100644
--- a/boards/mro/ctrl-zero-classic/nuttx-config/include/board.h
+++ b/boards/mro/ctrl-zero-classic/nuttx-config/include/board.h
@@ -197,6 +197,12 @@
 
 #define STM32_FDCANCLK               STM32_HSE_FREQUENCY
 
+/* UART clock selection */
+/* reset to default to overwrite any changes done by any bootloader */
+
+#define STM32_RCC_D2CCIP2R_USART234578_SEL RCC_D2CCIP2R_USART234578SEL_RCC
+#define STM32_RCC_D2CCIP2R_USART16_SEL     RCC_D2CCIP2R_USART16SEL_RCC
+
 /* FLASH wait states */
 #define BOARD_FLASH_WAITSTATES 2
 
diff --git a/boards/mro/ctrl-zero-h7-oem/nuttx-config/include/board.h b/boards/mro/ctrl-zero-h7-oem/nuttx-config/include/board.h
index d5ffa2c5848e..14a6a28d2b88 100644
--- a/boards/mro/ctrl-zero-h7-oem/nuttx-config/include/board.h
+++ b/boards/mro/ctrl-zero-h7-oem/nuttx-config/include/board.h
@@ -197,6 +197,12 @@
 
 #define STM32_FDCANCLK               STM32_HSE_FREQUENCY
 
+/* UART clock selection */
+/* reset to default to overwrite any changes done by any bootloader */
+
+#define STM32_RCC_D2CCIP2R_USART234578_SEL RCC_D2CCIP2R_USART234578SEL_RCC
+#define STM32_RCC_D2CCIP2R_USART16_SEL     RCC_D2CCIP2R_USART16SEL_RCC
+
 /* FLASH wait states */
 #define BOARD_FLASH_WAITSTATES 2
 
diff --git a/boards/mro/ctrl-zero-h7/nuttx-config/include/board.h b/boards/mro/ctrl-zero-h7/nuttx-config/include/board.h
index cdbd3dd3e629..4a20575d70ae 100644
--- a/boards/mro/ctrl-zero-h7/nuttx-config/include/board.h
+++ b/boards/mro/ctrl-zero-h7/nuttx-config/include/board.h
@@ -196,6 +196,12 @@
 
 #define STM32_FDCANCLK               STM32_HSE_FREQUENCY
 
+/* UART clock selection */
+/* reset to default to overwrite any changes done by any bootloader */
+
+#define STM32_RCC_D2CCIP2R_USART234578_SEL RCC_D2CCIP2R_USART234578SEL_RCC
+#define STM32_RCC_D2CCIP2R_USART16_SEL     RCC_D2CCIP2R_USART16SEL_RCC
+
 /* FLASH wait states */
 #define BOARD_FLASH_WAITSTATES 2
 
diff --git a/boards/mro/pixracerpro/nuttx-config/include/board.h b/boards/mro/pixracerpro/nuttx-config/include/board.h
index 5edda931dc10..96b2ed2022fb 100644
--- a/boards/mro/pixracerpro/nuttx-config/include/board.h
+++ b/boards/mro/pixracerpro/nuttx-config/include/board.h
@@ -196,6 +196,12 @@
 
 #define STM32_FDCANCLK               STM32_HSE_FREQUENCY
 
+/* UART clock selection */
+/* reset to default to overwrite any changes done by any bootloader */
+
+#define STM32_RCC_D2CCIP2R_USART234578_SEL RCC_D2CCIP2R_USART234578SEL_RCC
+#define STM32_RCC_D2CCIP2R_USART16_SEL     RCC_D2CCIP2R_USART16SEL_RCC
+
 /* FLASH wait states */
 #define BOARD_FLASH_WAITSTATES 2