diff --git a/libraries/SD/SD.cpp b/libraries/SD/SD.cpp
index e76ad7d7970..86bd5919a35 100644
--- a/libraries/SD/SD.cpp
+++ b/libraries/SD/SD.cpp
@@ -52,10 +52,6 @@
 
 #include "SD.h"
 
-// Use this to configure the chip select pin of the SD card.
-#define SD_CARD_CHIP_SELECT_PIN 4 // For use with Arduino Ethernet Shield
-
-
 // Used by `getNextPathComponent`
 #define MAX_COMPONENT_LEN 12 // What is max length?
 #define PATH_COMPONENT_BUFFER_LEN MAX_COMPONENT_LEN+1
@@ -311,7 +307,9 @@ boolean callback_openPath(SdFile& parentDir, char *filePathComponent,
 
 /* Implementation of class used to create `SDCard` object. */
 
-void SDClass::begin() {
+
+
+void SDClass::begin(uint8_t csPin) {
   /*
 
     Performs the initialisation required by the sdfatlib library.
@@ -320,7 +318,7 @@ void SDClass::begin() {
 
    */
   // TODO: Allow chip select pin to be supplied?
-  if (!(card.init(SPI_HALF_SPEED, SD_CARD_CHIP_SELECT_PIN) 
+  if (!(card.init(SPI_HALF_SPEED, csPin) 
 	&& volume.init(card) && root.openRoot(volume))) {
     while (true) {
       // Bail
diff --git a/libraries/SD/SD.h b/libraries/SD/SD.h
index bfce4239315..1c0479798ce 100644
--- a/libraries/SD/SD.h
+++ b/libraries/SD/SD.h
@@ -1,6 +1,6 @@
 /*
 
- MemoryCard - a slightly more friendly wrapper for sdfatlib
+ SD - a slightly more friendly wrapper for sdfatlib
 
  This library aims to expose a subset of SD card functionality
  in the form of a higher level "wrapper" object.
@@ -20,6 +20,9 @@
 #include <utility/SdFat.h>
 #include <utility/SdFatUtil.h>
 
+// Use this to configure the chip select pin of the SD card.
+#define SD_CARD_CHIP_SELECT_PIN 4 // For use with Arduino Ethernet Shield
+
 class SDClass {
 
  private:
@@ -32,7 +35,7 @@ class SDClass {
  public:
   // This needs to be called to set up the connection to the memory card
   // before other methods are used.
-  void begin();
+  void begin(uint8_t csPin = SD_CARD_CHIP_SELECT_PIN);
   
   // Open the specified file/directory with the supplied mode (e.g. read or
   // write, etc). Once opened the file can be accessed via the