diff --git a/libraries/AP_HAL/AP_HAL_Boards.h b/libraries/AP_HAL/AP_HAL_Boards.h
index 24b6a66d3b..cd9dab2565 100644
--- a/libraries/AP_HAL/AP_HAL_Boards.h
+++ b/libraries/AP_HAL/AP_HAL_Boards.h
@@ -381,4 +381,8 @@
 #error "HAL_GPIO_LED_OFF must not be defined, it is implicitly !HAL_GPIO_LED_ON"
 #endif
 
+#ifndef HAL_WITH_POSTYPE_DOUBLE
+#define HAL_WITH_POSTYPE_DOUBLE BOARD_FLASH_SIZE > 1024
+#endif
+
 #define HAL_GPIO_LED_OFF (!HAL_GPIO_LED_ON)