diff --git a/os/hal/ports/STM32/LLD/sdc_lld.h b/os/hal/ports/STM32/LLD/sdc_lld.h
index f4a44d18c..6f0e389d6 100644
--- a/os/hal/ports/STM32/LLD/sdc_lld.h
+++ b/os/hal/ports/STM32/LLD/sdc_lld.h
@@ -82,7 +82,14 @@
  * @brief   Read timeout in milliseconds.
  */
 #if !defined(STM32_SDC_READ_TIMEOUT_MS) || defined(__DOXYGEN__)
-#define STM32_SDC_READ_TIMEOUT_MS           5
+#define STM32_SDC_READ_TIMEOUT_MS           25
+#endif
+
+/**
+ * @brief   Card clock activation delay in milliseconds.
+ */
+#if !defined(STM32_SDC_CLOCK_ACTIVATION_DELAY) || defined(__DOXYGEN__)
+#define STM32_SDC_CLOCK_ACTIVATION_DELAY    10
 #endif
 
 /**
diff --git a/os/hal/src/sdc.c b/os/hal/src/sdc.c
index d18f37b55..c75397291 100644
--- a/os/hal/src/sdc.c
+++ b/os/hal/src/sdc.c
@@ -200,6 +200,9 @@ bool sdcConnect(SDCDriver *sdcp) {
   /* Card clock initialization.*/
   sdc_lld_start_clk(sdcp);
 
+  /* Clock activation delay.*/
+  osalThreadSleep(MS2ST(STM32_SDC_CLOCK_ACTIVATION_DELAY));
+
   /* Enforces the initial card state.*/
   sdc_lld_send_cmd_none(sdcp, MMCSD_CMD_GO_IDLE_STATE, 0);