diff --git a/ssl/handshake_server.cc b/ssl/handshake_server.cc
index c8a23a1..29fc3a4 100644
--- a/ssl/handshake_server.cc
+++ b/ssl/handshake_server.cc
@@ -973,8 +973,7 @@
 }
 
 static void copy_suffix(Span<uint8_t> out, Span<const uint8_t> in) {
-  out = out.subspan(out.size() - in.size());
-  assert(out.size() == in.size());
+  out = out.last(in.size());
   OPENSSL_memcpy(out.data(), in.data(), in.size());
 }