diff --git a/miosix/arch/common/drivers/sd_stm32f2_f4_f7.cpp b/miosix/arch/common/drivers/sd_stm32f2_f4_f7.cpp
index a719c8e723e5fc8b45900bbf4feda2d579c63d00..aaa4014411601ab8c4b1a8c4e5d46f38e05985fa 100644
--- a/miosix/arch/common/drivers/sd_stm32f2_f4_f7.cpp
+++ b/miosix/arch/common/drivers/sd_stm32f2_f4_f7.cpp
@@ -801,7 +801,7 @@ private:
     #endif //SD_ONE_BIT_DATABUS
 
     ///\internal Maximum number of calls to IRQreduceClockSpeed() allowed
-    static const unsigned char MAX_ALLOWED_REDUCTIONS=1;
+    static const unsigned char MAX_ALLOWED_REDUCTIONS=5;
 
     ///\internal value returned by getRetryCount() while *not* calibrating clock.
     static const unsigned char MAX_RETRY=10;