diff --git a/arch/arm/src/stm32/stm32l15xx_flash.c b/arch/arm/src/stm32/stm32l15xx_flash.c
index 28daa43ab2..3509dc9f0d 100644
--- a/arch/arm/src/stm32/stm32l15xx_flash.c
+++ b/arch/arm/src/stm32/stm32l15xx_flash.c
@@ -52,6 +52,7 @@
 #include <nuttx/arch.h>
 #include <nuttx/semaphore.h>
 
+#include <inttypes.h>
 #include <stdbool.h>
 #include <assert.h>
 #include <errno.h>
@@ -564,7 +565,8 @@ out:
 
   if (ret != OK)
     {
-      ferr("flash write error: %d, status: 0x%x\n", ret, getreg32(STM32_FLASH_SR));
+      ferr("flash write error: %d, status: 0x%" PRIx32 "\n",
+           ret, getreg32(STM32_FLASH_SR));
       modifyreg32(STM32_FLASH_SR, 0, FLASH_SR_ALLERRS);
     }