diff --git a/SPIFBlockDevice.h b/SPIFBlockDevice.h
index b9d0f7ef05..a443da02a5 100644
--- a/SPIFBlockDevice.h
+++ b/SPIFBlockDevice.h
@@ -58,7 +58,7 @@ public:
      *  @param csel     SPI chip select pin
      *  @param freq     Clock speed of the SPI bus (defaults to 40MHz)
      */
-    SPIFBlockDevice(PinName mosi, PinName miso, PinName sclk, PinName csel, int freq=4000000);
+    SPIFBlockDevice(PinName mosi, PinName miso, PinName sclk, PinName csel, int freq=40000000);
 
     /** Initialize a block device
      *