diff --git a/nuttx-configs/px4fmu-v5/include/board.h b/nuttx-configs/px4fmu-v5/include/board.h
index f7fd33ecf9..528c24e577 100755
--- a/nuttx-configs/px4fmu-v5/include/board.h
+++ b/nuttx-configs/px4fmu-v5/include/board.h
@@ -159,7 +159,7 @@
 #define STM32_RCC_DCKCFGR2_CK48MSRC   RCC_DCKCFGR2_CK48MSEL_PLL
 #define STM32_RCC_DCKCFGR2_SDMMCSRC   RCC_DCKCFGR2_SDMMCSEL_48MHZ
 #define STM32_RCC_DCKCFGR2_SDMMC2SRC  RCC_DCKCFGR2_SDMMC2SEL_48MHZ
-#define STM32_RCC_DCKCFGR2_DSISRC     RCC_DCKCFGR2_DSISEL_48MHZ
+#define STM32_RCC_DCKCFGR2_DSISRC     RCC_DCKCFGR2_DSISEL_PHY
 
 
 /* Several prescalers allow the configuration of the two AHB buses, the