diff --git a/exosphere/src/masterkey.c b/exosphere/src/masterkey.c
index c126a4af3..4b83da88a 100644
--- a/exosphere/src/masterkey.c
+++ b/exosphere/src/masterkey.c
@@ -3,6 +3,7 @@
 #include <string.h>
 
 #include "utils.h"
+#include "configitem.h"
 #include "masterkey.h"
 #include "se.h"
 
@@ -12,9 +13,19 @@ static bool g_determined_mkey_revision = false;
 static uint8_t g_old_masterkeys[MASTERKEY_REVISION_MAX][0x10];
 static uint8_t g_old_devicekeys[MASTERKEY_NUM_NEW_DEVICE_KEYS - 1][0x10];
 
-/* TODO: Dev keys. */
 
 /* TODO: Extend with new vectors, as needed. */
+/* Dev unit keys. */
+static const uint8_t mkey_vectors_dev[MASTERKEY_REVISION_MAX][0x10] =
+{
+    {0x46, 0x22, 0xB4, 0x51, 0x9A, 0x7E, 0xA7, 0x7F, 0x62, 0xA1, 0x1F, 0x8F, 0xC5, 0x3A, 0xDB, 0xFE}, /* Zeroes encrypted with Master Key 00. */
+    {0x39, 0x33, 0xF9, 0x31, 0xBA, 0xE4, 0xA7, 0x21, 0x2C, 0xDD, 0xB7, 0xD8, 0xB4, 0x4E, 0x37, 0x23}, /* Master key 00 encrypted with Master key 01. */
+    {0x97, 0x29, 0xB0, 0x32, 0x43, 0x14, 0x8C, 0xA6, 0x85, 0xE9, 0x5A, 0x94, 0x99, 0x39, 0xAC, 0x5D}, /* Master key 01 encrypted with Master key 02. */
+    {0x2C, 0xCA, 0x9C, 0x31, 0x1E, 0x07, 0xB0, 0x02, 0x97, 0x0A, 0xD8, 0x03, 0xA2, 0x76, 0x3F, 0xA3}, /* Master key 02 encrypted with Master key 03. */
+    {0x9B, 0x84, 0x76, 0x14, 0x72, 0x94, 0x52, 0xCB, 0x54, 0x92, 0x9B, 0xC4, 0x8C, 0x5B, 0x0F, 0xBA}, /* Master key 03 encrypted with Master key 04. */
+};
+
+/* Retail unit keys. */
 static const uint8_t mkey_vectors[MASTERKEY_REVISION_MAX][0x10] =
 {
     {0x0C, 0xF0, 0x59, 0xAC, 0x85, 0xF6, 0x26, 0x65, 0xE1, 0xE9, 0x19, 0x55, 0xE6, 0xF2, 0x67, 0x3D}, /* Zeroes encrypted with Master Key 00. */
@@ -24,14 +35,14 @@ static const uint8_t mkey_vectors[MASTERKEY_REVISION_MAX][0x10] =
     {0x6E, 0x7D, 0x2D, 0xC3, 0x0F, 0x59, 0xC8, 0xFA, 0x87, 0xA8, 0x2E, 0xD5, 0x89, 0x5E, 0xF3, 0xE9}, /* Master key 03 encrypted with Master key 04. */
 };
 
-bool check_mkey_revision(unsigned int revision) {
+bool check_mkey_revision(unsigned int revision, bool is_retail) {
     uint8_t final_vector[0x10];
 
     unsigned int check_keyslot = KEYSLOT_SWITCH_MASTERKEY;
     if (revision > 0) {
         /* Generate old master key array. */
         for (unsigned int i = revision; i > 0; i--) {
-            se_aes_ecb_decrypt_block(check_keyslot, g_old_masterkeys[i-1], 0x10, mkey_vectors[i], 0x10);
+            se_aes_ecb_decrypt_block(check_keyslot, g_old_masterkeys[i-1], 0x10, is_retail ? mkey_vectors[i] : mkey_vectors_dev[i], 0x10);
             set_aes_keyslot(KEYSLOT_SWITCH_TEMPKEY, g_old_masterkeys[i-1], 0x10);
             check_keyslot = KEYSLOT_SWITCH_TEMPKEY;
         }
@@ -52,7 +63,7 @@ void mkey_detect_revision(void) {
     }
     
     for (unsigned int rev = 0; rev < MASTERKEY_REVISION_MAX; rev++) {
-        if (check_mkey_revision(rev)) {
+        if (check_mkey_revision(rev, configitem_is_retail())) {
             g_determined_mkey_revision = true;
             g_mkey_revision = rev;
             break;