diff --git a/lib/picotls.c b/lib/picotls.c
index 187c862..47d8c26 100644
--- a/lib/picotls.c
+++ b/lib/picotls.c
@@ -6341,7 +6341,7 @@
             }
         });
         ptls_buffer_push(buf, max_name_length);
-        ptls_buffer_push_block(buf, 2, { ptls_buffer_pushv(buf, public_name, strlen(public_name)); });
+        ptls_buffer_push_block(buf, 1, { ptls_buffer_pushv(buf, public_name, strlen(public_name)); });
         ptls_buffer_push_block(buf, 2, {/* extensions */});
     });