diff --git a/source/fatfs/sdmmc/sdmmc.c b/source/fatfs/sdmmc/sdmmc.c
index 74901e0..27966a1 100644
--- a/source/fatfs/sdmmc/sdmmc.c
+++ b/source/fatfs/sdmmc/sdmmc.c
@@ -107,8 +107,8 @@ static void __attribute__ ((noinline)) sdmmc_send_command(struct mmcdevice *ctx,
     u8 *rDataPtr = ctx->rData;
     const u8 *tDataPtr = ctx->tData;
 
-    int rUseBuf = NULL != rDataPtr;
-    int tUseBuf = NULL != tDataPtr;
+    bool rUseBuf = rDataPtr != NULL;
+    bool tUseBuf = tDataPtr != NULL;
 
     u16 status0 = 0;
     while(true)