diff --git a/libraries/AP_HAL_ChibiOS/hwdef/fmuv3/hwdef.dat b/libraries/AP_HAL_ChibiOS/hwdef/fmuv3/hwdef.dat
index 7b8cf98f57..77f98b356c 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/fmuv3/hwdef.dat
+++ b/libraries/AP_HAL_ChibiOS/hwdef/fmuv3/hwdef.dat
@@ -99,7 +99,7 @@ PD7 BARO_CS CS
 # USART3 serial3 telem2
 PD8 USART3_TX USART3
 PD9 USART3_RX USART3
-PD10 FRAM_CS CS SPEED_LOW
+PD10 FRAM_CS CS SPEED_VERYLOW
 PD11 USART3_CTS USART3
 PD12 USART3_RTS USART3
 PD13 TIM4_CH2 TIM4 PWM(5) GPIO(54)
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
index 7b07166b4e..6917f006f5 100755
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
@@ -169,12 +169,9 @@ class generic_pin(object):
 
         def get_OSPEEDR(self):
                 '''return one of SPEED_VERYLOW, SPEED_LOW, SPEED_MEDIUM, SPEED_HIGH'''
+                # on STM32F4 these speeds correspond to 2MHz, 25MHz, 50MHz and 100MHz
                 values = ['SPEED_VERYLOW', 'SPEED_LOW', 'SPEED_MEDIUM', 'SPEED_HIGH']
-                v = 'SPEED_HIGH'
-                if self.is_CS():
-                        v = "SPEED_MEDIUM"
-                if self.type.startswith("I2C"):
-                        v = "SPEED_MEDIUM"
+                v = 'SPEED_MEDIUM'
                 for e in self.extra:
                         if e in values:
                                 v = e