diff --git a/ports/raspberrypi/Makefile b/ports/raspberrypi/Makefile
index 413480d108..2c1a13a8b2 100644
--- a/ports/raspberrypi/Makefile
+++ b/ports/raspberrypi/Makefile
@@ -234,7 +234,7 @@ SRC_COMMON_HAL_SHARED_MODULE_EXPANDED = $(sort $(SRC_COMMON_HAL_EXPANDED) $(SRC_
 
 SRC_S = supervisor/$(CHIP_FAMILY)_cpu.s
 BOOT2_S_UPPER ?= sdk/src/rp2_common/boot_stage2/boot2_generic_03h.S
-BOOT2_S_CFLAGS ?= -DPICO_FLASH_SPI_CLKDIV=6
+BOOT2_S_CFLAGS ?= -DPICO_FLASH_SPI_CLKDIV=4
 SRC_S_UPPER = sdk/src/rp2_common/hardware_divider/divider.S \
               sdk/src/rp2_common/hardware_irq/irq_handler_chain.S \
               sdk/src/rp2_common/pico_bit_ops/bit_ops_aeabi.S \