diff --git a/lib/libmd5sum/md5.c b/lib/libmd5sum/md5.c
index 3e7aa83ed..e433782e8 100644
--- a/lib/libmd5sum/md5.c
+++ b/lib/libmd5sum/md5.c
@@ -96,8 +96,8 @@ md5_finish_ctx (ctx, resbuf)
 {
   /* Take yet unprocessed bytes into account.  */
   md5_uint32 bytes = ctx->buflen;
+  md5_uint32 swap_bytes;
   size_t pad;
-  md5_uint32 *p;
 
   /* Now count remaining bytes.  */
   ctx->total[0] += bytes;
@@ -107,11 +107,13 @@ md5_finish_ctx (ctx, resbuf)
   pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
   memmove (&ctx->buffer[bytes], fillbuf, pad);
 
-  /* Put the 64-bit file length in *bits* at the end of the buffer.  */
-  p = (md5_uint32 *)&ctx->buffer[bytes + pad];
-  *p = SWAP (ctx->total[0] << 3);
-  p++;
-  *p = SWAP ((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.  */
+  swap_bytes = SWAP (ctx->total[0] << 3);
+  memcpy (&ctx->buffer[bytes + pad], &swap_bytes, sizeof (swap_bytes));
+  swap_bytes = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
+  memcpy (&ctx->buffer[bytes + pad + 4], &swap_bytes, sizeof (swap_bytes));
 
   /* Process last bytes.  */
   md5_process_block (ctx->buffer, bytes + pad + 8, ctx);