diff --git a/roles/copr/backend/files/provision/files/mock/site-defaults.cfg b/roles/copr/backend/files/provision/files/mock/site-defaults.cfg
index 05bafe209b..9e1d1698ec 100644
--- a/roles/copr/backend/files/provision/files/mock/site-defaults.cfg
+++ b/roles/copr/backend/files/provision/files/mock/site-defaults.cfg
@@ -40,3 +40,7 @@ config_opts['nspawn_args'] += ['--rlimit=RLIMIT_NOFILE=10240']
 # also I believe it is releated to this:
 # https://github.com/rpm-software-management/mock/issues/186
 config_opts['nspawn_args'] += ['--capability=cap_ipc_lock']
+
+# bootstrap chroot is disabled by default, so we don't want to block
+# the build by this warning
+config_opts['dnf_warning'] = False