diff --git a/src/crypto/CryptonightR_JIT.c b/src/crypto/CryptonightR_JIT.c
index b59af8c09..968f454ee 100644
--- a/src/crypto/CryptonightR_JIT.c
+++ b/src/crypto/CryptonightR_JIT.c
@@ -102,7 +102,7 @@ int v4_generate_JIT_code(const struct V4_Instruction* code, v4_random_math_JIT_f
 		APPEND_CODE(p1, p2 - p1);
 
 		if (inst.opcode == ADD)
-			*(uint32_t*)(JIT_code - 4) = inst.C;
+			memcpy(JIT_code - 4, &inst.C, sizeof(inst.C));
 	}
 
 	APPEND_CODE(epilogue, sizeof(epilogue));
diff --git a/src/crypto/hash-ops.h b/src/crypto/hash-ops.h
index 4323fa70c..9250e4f93 100644
--- a/src/crypto/hash-ops.h
+++ b/src/crypto/hash-ops.h
@@ -39,6 +39,7 @@
 
 #include <assert.h>
 #include <stdbool.h>
+#include <stdalign.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -65,13 +66,12 @@ static inline void place_length(uint8_t *buffer, size_t bufsize, size_t length)
 }
 POP_WARNINGS
 
-#pragma pack(push, 1)
 union hash_state {
   uint8_t b[200];
   uint64_t w[25];
 };
-#pragma pack(pop)
 static_assert(sizeof(union hash_state) == 200, "Invalid structure size");
+static_assert(alignof(union hash_state) == alignof(uint64_t), "Invalid structure alignment");
 
 void hash_permutation(union hash_state *state);
 void hash_process(union hash_state *state, const uint8_t *buf, size_t count);
diff --git a/src/crypto/keccak.c b/src/crypto/keccak.c
index 6616d3530..62e574bfa 100644
--- a/src/crypto/keccak.c
+++ b/src/crypto/keccak.c
@@ -119,50 +119,49 @@ typedef uint64_t state_t[25];
 void keccak(const uint8_t *in, size_t inlen, uint8_t *md, int mdlen)
 {
     state_t st;
-    uint8_t temp[144];
+    uint64_t temp[18];
     size_t i, rsiz, rsizw;
 
-    static_assert(HASH_DATA_AREA <= sizeof(temp), "Bad keccak preconditions");
-    if (mdlen <= 0 || (mdlen >= 100 && sizeof(st) != (size_t)mdlen))
+    static_assert(HASH_DATA_AREA + sizeof(uint64_t) == sizeof(temp), "Bad keccak preconditions");
+    if (mdlen <= 0 || (mdlen >= 100 && sizeof(st) != (size_t)mdlen) || ((size_t)mdlen % sizeof(uint64_t)) != 0)
     {
       local_abort("Bad keccak use");
     }
 
     rsiz = sizeof(state_t) == mdlen ? HASH_DATA_AREA : 200 - 2 * mdlen;
     rsizw = rsiz / 8;
+    if (rsiz == 0 || rsiz > sizeof(temp) || rsizw * sizeof(uint64_t) > sizeof(temp))
+    {
+      local_abort("Bad keccak use");
+    }
     
     memset(st, 0, sizeof(st));
 
     for ( ; inlen >= rsiz; inlen -= rsiz, in += rsiz) {
+      memcpy(temp, in, rsiz);
       for (i = 0; i < rsizw; i++) {
-        uint64_t ina;
-        memcpy(&ina, in + i * 8, 8);
-        st[i] ^= swap64le(ina);
+        st[i] ^= SWAP64LE(temp[i]);
       }
       keccakf(st, KECCAK_ROUNDS);
     }
     
     // last block and padding
-    if (inlen + 1 >= sizeof(temp) || inlen > rsiz || rsiz - inlen + inlen + 1 >= sizeof(temp) || rsiz == 0 || rsiz - 1 >= sizeof(temp) || rsizw * 8 > sizeof(temp))
+    memset(temp, 0, sizeof(temp));
+    if (inlen >= rsiz)
     {
       local_abort("Bad keccak use");
     }
-
     if (inlen > 0)
       memcpy(temp, in, inlen);
-    temp[inlen++] = 1;
-    memset(temp + inlen, 0, rsiz - inlen);
-    temp[rsiz - 1] |= 0x80;
+    ((uint8_t *) temp)[inlen] = 1;
+    ((uint8_t *) temp)[rsiz - 1] |= 0x80;
 
-    for (i = 0; i < rsizw; i++)
-        st[i] ^= swap64le(((uint64_t *) temp)[i]);
+    for (i = 0; i < rsizw; i++) {
+      st[i] ^= SWAP64LE(temp[i]);
+    }
 
     keccakf(st, KECCAK_ROUNDS);
 
-    if (((size_t)mdlen % sizeof(uint64_t)) != 0)
-    {
-      local_abort("Bad keccak use");
-    }
     memcpy_swap64le(md, st, mdlen/sizeof(uint64_t));
 }
 
diff --git a/src/crypto/slow-hash.c b/src/crypto/slow-hash.c
index 305786aa1..f2f7e930f 100644
--- a/src/crypto/slow-hash.c
+++ b/src/crypto/slow-hash.c
@@ -155,11 +155,14 @@ static inline int force_software_aes(void)
   } while(0)
 
 #define VARIANT1_INIT64() \
+  uint64_t tweak1_2 = 0; \
   if (variant == 1) \
   { \
+    uint64_t nonce; \
     VARIANT1_CHECK(); \
-  } \
-  const uint64_t tweak1_2 = (variant == 1) ? (state.hs.w[24] ^ (*((const uint64_t*)NONCE_POINTER))) : 0
+    memcpy(&nonce, NONCE_POINTER, sizeof(nonce)); \
+    tweak1_2 = state.hs.w[24] ^ nonce; \
+  }
 
 #define VARIANT2_INIT64() \
   uint64_t division_result = 0; \
@@ -469,7 +472,6 @@ static inline int force_software_aes(void)
   _b1 = _b; \
   _b = _c; \
 
-#pragma pack(push, 1)
 union cn_slow_hash_state
 {
     union hash_state hs;
@@ -479,7 +481,6 @@ union cn_slow_hash_state
         uint8_t init[INIT_SIZE_BYTE];
     };
 };
-#pragma pack(pop)
 
 THREADV uint8_t *hp_state = NULL;
 THREADV int hp_allocated = 0;
@@ -1086,7 +1087,6 @@ STATIC INLINE void xor64(uint64_t *a, const uint64_t b)
     *a ^= b;
 }
 
-#pragma pack(push, 1)
 union cn_slow_hash_state
 {
     union hash_state hs;
@@ -1096,7 +1096,6 @@ union cn_slow_hash_state
         uint8_t init[INIT_SIZE_BYTE];
     };
 };
-#pragma pack(pop)
 
 #if defined(__aarch64__) && defined(__ARM_FEATURE_CRYPTO)
 
@@ -1767,7 +1766,6 @@ static void xor64(uint8_t* left, const uint8_t* right)
   }
 }
 
-#pragma pack(push, 1)
 union cn_slow_hash_state {
   union hash_state hs;
   struct {
@@ -1775,7 +1773,6 @@ union cn_slow_hash_state {
     uint8_t init[INIT_SIZE_BYTE];
   };
 };
-#pragma pack(pop)
 
 void cn_slow_hash(const void *data, size_t length, char *hash, int variant, int prehashed, uint64_t height) {
 #ifndef FORCE_USE_HEAP