diff --git a/board/drivers/uart_declarations.h b/board/drivers/uart_declarations.h
index 14ec2611..3096aed2 100644
--- a/board/drivers/uart_declarations.h
+++ b/board/drivers/uart_declarations.h
@@ -1,7 +1,11 @@
 #pragma once
 
 // ***************************** Definitions *****************************
+#ifdef STM32H7
 #define FIFO_SIZE_INT 0x400U
+#else
+#define FIFO_SIZE_INT 0x200U
+#endif
 
 typedef struct uart_ring {
   volatile uint16_t w_ptr_tx;