--- a/src/sha.c
+++ b/src/sha.c
@@ -78,6 +78,7 @@ sha_finish_ctx (struct sha_ctx *ctx, voi
 {
   /* Take yet unprocessed bytes into account.  */
   md5_uint32 bytes = ctx->buflen;
+  md5_uint32 notswap_bytes;
   size_t pad;
 
   /* Now count remaining bytes.  */
@@ -88,10 +89,13 @@ sha_finish_ctx (struct sha_ctx *ctx, voi
   pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
   memcpy (&ctx->buffer[bytes], fillbuf, pad);
 
-  /* Put the 64-bit file length in *bits* at the end of the buffer.  */
-  *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = NOTSWAP (ctx->total[0] << 3);
-  *(md5_uint32 *) &ctx->buffer[bytes + pad] = NOTSWAP ((ctx->total[1] << 3) |
-						    (ctx->total[0] >> 29));
+  /* Put the 64-bit file length in *bits* at the end of the buffer.
+     Use memcpy to avoid aliasing problems.  On most systems, this
+     will be optimized away to the same code.  */
+  notswap_bytes = NOTSWAP (ctx->total[0] << 3);
+  memcpy (&ctx->buffer[bytes + pad + 4], notswap_bytes, sizeof (notswap_bytes));
+  notswap_bytes = NOTSWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
+  memcpy (&ctx->buffer[bytes + pad], notswap_bytes, sizeof (notswap_bytes));
 
   /* Process last bytes.  */
   sha_process_block (ctx->buffer, bytes + pad + 8, ctx);