diff --git a/windows/wincapi.c b/windows/wincapi.c
index 8059f753..de78988b 100644
--- a/windows/wincapi.c
+++ b/windows/wincapi.c
@@ -71,7 +71,11 @@ char *capi_obfuscate_string(const char *realname)
      * We don't want to give away the length of the hostname either,
      * so having got it back out of CryptProtectMemory we now hash it.
      */
-    hash_simple(&ssh_sha256, make_ptrlen(cryptdata, cryptlen), digest);
+    {
+        ssh_hash *h = ssh_hash_new(&ssh_sha256);
+        put_string(h, cryptdata, cryptlen);
+        ssh_hash_final(h, digest);
+    }
 
     sfree(cryptdata);