diff --git a/include/arm9/crypto.h b/include/arm9/crypto.h
index 161a17e..7318f78 100644
--- a/include/arm9/crypto.h
+++ b/include/arm9/crypto.h
@@ -67,6 +67,11 @@
 void AES_init(void);
 
 /**
+ * @brief      Deinits AES to workaround a K9L bug.
+ */
+void AES_deinit(void);
+
+/**
  * @brief      Sets a AES key in the specified keyslot.
  *
  * @param[in]  keyslot         The keyslot this key will be set for.
diff --git a/source/arm9/crypto.c b/source/arm9/crypto.c
index bb1a1af..7f5533b 100644
--- a/source/arm9/crypto.c
+++ b/source/arm9/crypto.c
@@ -156,6 +156,11 @@
 	setupKeys();
 }
 
+void AES_deinit(void)
+{
+	REG_AESCNT = AES_MAC_SIZE(4) | AES_FLUSH_WRITE_FIFO | AES_FLUSH_READ_FIFO;
+}
+
 void AES_setKey(u8 keyslot, AesKeyType type, u8 orderEndianess, bool twlScrambler, const u32 key[4])
 {
 	assert(keyslot < 0x40);
diff --git a/source/arm9/hardware.c b/source/arm9/hardware.c
index 1388e7f..4ab323a 100644
--- a/source/arm9/hardware.c
+++ b/source/arm9/hardware.c
@@ -20,5 +20,5 @@
 {
 	// New 3DS K9L doesn't like FIFO counts >4 and hangs.
 	// Thx Nintendo
-	AES_init();
+	AES_deinit();
 }