diff --git a/mock/etc/mock/hermetic-build.cfg b/mock/etc/mock/hermetic-build.cfg
index 79416de34..4bcfe1d5f 100644
--- a/mock/etc/mock/hermetic-build.cfg
+++ b/mock/etc/mock/hermetic-build.cfg
@@ -10,6 +10,10 @@ config_opts['description'] = 'Configuration file for Hermetic Builds'
 # with creating caches.
 config_opts['plugin_conf']['root_cache_enable'] = False
 
+# Normal bootstrapping needs networking to be ON, but hermetic builds don't.
+bootstrap_buildroot_config['rpmbuild_networking'] = False
+bootstrap_buildroot_config['use_host_resolv'] = False
+
 config_opts['dnf.conf'] = """
 [main]
 keepcache=1
diff --git a/mock/py/mock.py b/mock/py/mock.py
index e4cc1634f..b050805d0 100755
--- a/mock/py/mock.py
+++ b/mock/py/mock.py
@@ -766,7 +766,6 @@ def main():
         # allow bootstrap buildroot to access the network for getting packages
         bootstrap_buildroot_config['rpmbuild_networking'] = True
         bootstrap_buildroot_config['use_host_resolv'] = True
-        util.setup_host_resolv(bootstrap_buildroot_config)
 
         # disable updating bootstrap chroot
         bootstrap_buildroot_config['update_before_build'] = False
@@ -812,6 +811,8 @@ def main():
             mount_point = BindMountPoint(srcpath=key_dir, bindpath=chroot_dir)
             bootstrap_buildroot.mounts.add(mount_point)
 
+        util.setup_host_resolv(bootstrap_buildroot_config)
+
     # this changes config_opts['nspawn_args'], so do it after initializing
     # bootstrap chroot to not inherit the changes there
     util.setup_host_resolv(config_opts)
diff --git a/mock/py/mockbuild/util.py b/mock/py/mockbuild/util.py
index 77ae6266c..432badbec 100644
--- a/mock/py/mockbuild/util.py
+++ b/mock/py/mockbuild/util.py
@@ -869,7 +869,7 @@ def setup_host_resolv(config_opts):
                 ::1       localhost localhost.localdomain localhost6 localhost6.localdomain6
                 ''')
 
-    if config_opts['isolation'] == 'simple':
+    if not USE_NSPAWN:
         # Not using nspawn -> don't touch /etc/resolv.conf; we already have
         # a valid file prepared by Buildroot._init() (if user requested).
         return