diff --git a/arm9/source/crypto/sha.c b/arm9/source/crypto/sha.c
index 0d9f737..7173d61 100644
--- a/arm9/source/crypto/sha.c
+++ b/arm9/source/crypto/sha.c
@@ -1,5 +1,10 @@
 #include "sha.h"
 
+typedef struct
+{
+	u32 data[16];
+} _sha_block;
+
 void sha_init(u32 mode)
 {
     while(*REG_SHACNT & 1);
@@ -12,16 +17,12 @@ void sha_update(const void* src, u32 size)
     
     while(size >= 0x40) {
         while(*REG_SHACNT & 1);
-        for(u32 i = 0; i < 4; i++) {
-            *REG_SHAINFIFO = *src32++;
-            *REG_SHAINFIFO = *src32++;
-            *REG_SHAINFIFO = *src32++;
-            *REG_SHAINFIFO = *src32++;
-        }
+        *((_sha_block*)REG_SHAINFIFO) = *((const _sha_block*)src32);
+        src32 += 16;
         size -= 0x40;
     }
     while(*REG_SHACNT & 1);
-    memcpy((void*)REG_SHAINFIFO, src32, size);
+    if(size) memcpy((void*)REG_SHAINFIFO, src32, size);
 }
 
 void sha_get(void* res) {
diff --git a/arm9/source/crypto/sha.h b/arm9/source/crypto/sha.h
index 10782da..a1b88ec 100644
--- a/arm9/source/crypto/sha.h
+++ b/arm9/source/crypto/sha.h
@@ -4,8 +4,8 @@
 
 #define REG_SHACNT      ((volatile uint32_t*)0x1000A000)
 #define REG_SHABLKCNT   ((volatile uint32_t*)0x1000A004)
-#define REG_SHAHASH     ((volatile uint32_t*)0x1000A040)
-#define REG_SHAINFIFO   ((volatile uint32_t*)0x1000A080)
+#define REG_SHAHASH     ((         uint32_t*)0x1000A040)
+#define REG_SHAINFIFO   (                    0x1000A080)
 
 #define SHA_CNT_STATE           0x00000003
 #define SHA_CNT_OUTPUT_ENDIAN   0x00000008