diff --git a/arch/arm/src/sam34/chip/sam3u_pio.h b/arch/arm/src/sam34/chip/sam3u_pio.h
index 0ce331d18de..c1cc045e7cf 100644
--- a/arch/arm/src/sam34/chip/sam3u_pio.h
+++ b/arch/arm/src/sam34/chip/sam3u_pio.h
@@ -58,7 +58,7 @@
                                           /* 0x000c: Reserved */
 #define SAM_PIO_OER_OFFSET         0x0010 /* Output Enable Register */
 #define SAM_PIO_ODR_OFFSET         0x0014 /* Output Disable Register */
-#define SAM_PIO_OSR_OFFSET         0x0018 /* utput Status Register */
+#define SAM_PIO_OSR_OFFSET         0x0018 /* Output Status Register */
                                           /* 0x001c: Reserved */
 #define SAM_PIO_IFER_OFFSET        0x0020 /* Glitch Input Filter Enable Register */
 #define SAM_PIO_IFDR_OFFSET        0x0024 /* Glitch Input Filter Disable Register */
@@ -444,6 +444,7 @@
 #define PIO_WPMR_WPEN              (1 << 0)  /* Bit 0:  Write Protect Enable */
 #define PIO_WPMR_WPKEY_SHIFT       (8)       /* Bits 8-31: Write Protect KEY */
 #define PIO_WPMR_WPKEY_MASK        (0xffffff << PIO_WPMR_WPKEY_SHIFT)
+#  define PIO_WPMR_WPKEY           (0x50494f << PIO_WPMR_WPKEY_SHIFT)
 
 /* PIO Write Protect Status Register */
 
diff --git a/arch/arm/src/sam34/sam3u_gpio.c b/arch/arm/src/sam34/sam3u_gpio.c
index a1ce7953fca..d94f2a3f867 100644
--- a/arch/arm/src/sam34/sam3u_gpio.c
+++ b/arch/arm/src/sam34/sam3u_gpio.c
@@ -377,6 +377,14 @@ int sam_configgpio(gpio_pinset_t cfgset)
   uint32_t  pin  = sam_gpiopin(cfgset);
   int       ret;
 
+  /* Enable writing to GPIO registers
+   * TODO:  This probably requires some protection against re-entry.
+   */
+
+  putreg32(PIO_WPMR_WPKEY, base + SAM_PIO_WPMR_OFFSET);
+
+  /* Handle the pin configuration according to pin type */
+
   switch (cfgset & GPIO_MODE_MASK)
     {
       case GPIO_INPUT:
@@ -400,6 +408,11 @@ int sam_configgpio(gpio_pinset_t cfgset)
         ret = -EINVAL;
         break;
     }
+
+  /* Enable writing to GPIO registers */
+
+  putreg32(PIO_WPMR_WPEN | PIO_WPMR_WPKEY, base + SAM_PIO_WPMR_OFFSET);
+
   return ret;
 }