diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32h7_mcuconf.h b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32h7_mcuconf.h
index 109d044b2d..82b4efa8ef 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32h7_mcuconf.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32h7_mcuconf.h
@@ -612,7 +612,7 @@
 #if STM32_WSPI_USE_QUADSPI1
 #define STM32_WSPI_QUADSPI1_MDMA_CHANNEL    STM32_MDMA_CHANNEL_ID_ANY
 #define STM32_WSPI_QUADSPI1_MDMA_PRIORITY   1
-#define STM32_WSPI_QUADSPI1_PRESCALER_VALUE ((STM32_QSPICLK / HAL_QSPI1_CLK) - 1)
+#define STM32_WSPI_QUADSPI1_PRESCALER_VALUE (STM32_QSPICLK / HAL_QSPI1_CLK)
 #endif
 
 /*