diff --git a/os/hal/ports/STM32/sdc_lld.h b/os/hal/ports/STM32/sdc_lld.h
index 9db4160dd..f4a44d18c 100644
--- a/os/hal/ports/STM32/sdc_lld.h
+++ b/os/hal/ports/STM32/sdc_lld.h
@@ -259,11 +259,11 @@ struct SDCDriver {
    * @brief     Transmit DMA channel.
    */
   const stm32_dma_stream_t  *dma;
+#if CH_DBG_ENABLE_ASSERTS || defined(__DOXYGEN__)
   /**
    * @brief     Pointer to the SDIO registers block.
    * @note      Used only for dubugging purpose.
    */
-#if CH_DBG_ENABLE_ASSERTS
   SDIO_TypeDef              *sdio;
 #endif
 };
diff --git a/testhal/STM32F4xx/SDC/main.c b/testhal/STM32F4xx/SDC/main.c
index f547f65e8..3a049234a 100644
--- a/testhal/STM32F4xx/SDC/main.c
+++ b/testhal/STM32F4xx/SDC/main.c
@@ -99,7 +99,7 @@ void cmd_sdc(BaseSequentialStream *chp, int argc, char *argv[]) {
     end = start + MS2ST(1000);
     n = 0;
     do {
-      if (blkRead(&SDCD1, startblk, buf, MMCSD_BLOCK_SIZE)) {
+      if (blkRead(&SDCD1, startblk, buf, 1)) {
         chprintf(chp, "failed\r\n");
         break;
       }