diff --git a/src/keccak.cpp b/src/keccak.cpp
index 67b13c6..795e190 100644
--- a/src/keccak.cpp
+++ b/src/keccak.cpp
@@ -48,17 +48,21 @@ NOINLINE void keccakf(uint64_t* st)
 		bc[3] = st[3] ^ st[8] ^ st[13] ^ st[18] ^ st[23];
 		bc[4] = st[4] ^ st[9] ^ st[14] ^ st[19] ^ st[24];
 
-		for (int i = 0; i < 5; ++i) {
-			uint64_t t = bc[(i + 4) % 5] ^ ROTL64(bc[(i + 1) % 5], 1);
-			st[i +  0 ] ^= t;
-			st[i +  5] ^= t;
-			st[i + 10] ^= t;
-			st[i + 15] ^= t;
-			st[i + 20] ^= t;
+#define X(i) { \
+			const uint64_t t = bc[(i + 4) % 5] ^ ROTL64(bc[(i + 1) % 5], 1); \
+			st[i +  0 ] ^= t; \
+			st[i +  5] ^= t; \
+			st[i + 10] ^= t; \
+			st[i + 15] ^= t; \
+			st[i + 20] ^= t; \
 		}
 
+		X(0); X(1); X(2); X(3); X(4);
+
+#undef X
+
 		// Rho Pi
-		uint64_t t = st[1];
+		const uint64_t t = st[1];
 		st[ 1] = ROTL64(st[ 6], 44);
 		st[ 6] = ROTL64(st[ 9], 20);
 		st[ 9] = ROTL64(st[22], 61);