diff --git a/hardware/arduino/sam/cores/arduino/wiring_constants.h b/hardware/arduino/sam/cores/arduino/wiring_constants.h
index 0555d71b0..868d46dbd 100644
--- a/hardware/arduino/sam/cores/arduino/wiring_constants.h
+++ b/hardware/arduino/sam/cores/arduino/wiring_constants.h
@@ -28,6 +28,7 @@ extern "C"{
 
 #define INPUT 0x0
 #define OUTPUT 0x1
+#define INPUT_PULLUP 0x2
 
 #define true 0x1
 #define false 0x0
diff --git a/hardware/arduino/sam/cores/arduino/wiring_digital.c b/hardware/arduino/sam/cores/arduino/wiring_digital.c
index 5d81034be..ac6eb18b8 100644
--- a/hardware/arduino/sam/cores/arduino/wiring_digital.c
+++ b/hardware/arduino/sam/cores/arduino/wiring_digital.c
@@ -41,6 +41,16 @@ extern void pinMode( uint32_t ulPin, uint32_t ulMode )
             	0 ) ;
         break ;
 
+        case INPUT_PULLUP:
+            /* Enable peripheral for clocking input */
+            pmc_enable_periph_clk( g_APinDescription[ulPin].ulPeripheralId ) ;
+            PIO_Configure(
+            	g_APinDescription[ulPin].pPort,
+            	PIO_INPUT,
+            	g_APinDescription[ulPin].ulPin,
+            	PIO_PULLUP ) ;
+        break ;
+
         case OUTPUT:
             PIO_Configure(
             	g_APinDescription[ulPin].pPort,