diff --git a/ports/raspberrypi/boards/pimoroni_keybow2040/mpconfigboard.h b/ports/raspberrypi/boards/pimoroni_keybow2040/mpconfigboard.h
index ecc127db68..234be27c2c 100644
--- a/ports/raspberrypi/boards/pimoroni_keybow2040/mpconfigboard.h
+++ b/ports/raspberrypi/boards/pimoroni_keybow2040/mpconfigboard.h
@@ -28,6 +28,8 @@
 #define DEFAULT_UART_BUS_RX (&pin_GPIO1)
 #define DEFAULT_UART_BUS_TX (&pin_GPIO0)
 
+#define TOTAL_FLASH_SIZE (2 * 1024 * 1024)
+
 // These pins are unconnected
 #define IGNORE_PIN_GPIO2    1
 #define IGNORE_PIN_GPIO22   1