diff --git a/src/ovirt_hosted_engine_setup/ansible_utils.py b/src/ovirt_hosted_engine_setup/ansible_utils.py
index bfd5205a..0fb890d0 100644
--- a/src/ovirt_hosted_engine_setup/ansible_utils.py
+++ b/src/ovirt_hosted_engine_setup/ansible_utils.py
@@ -222,14 +222,20 @@ def run(self):
                         self._process_output(buffer)
                         buffer = ''
             rc = proc.poll()
-            self._cb_results['ansible-playbook_rc'] = rc
             self.logger.debug('ansible-playbook rc: {rc}'.format(rc=rc))
+            # A RESULT line read below replaces _cb_results, so store the
+            # return code only after the callback file is drained.
             while True:
                 output = out_fh.readline()
                 if output == '':
                     break
-                if output:
-                    self._process_output(output)
+                buffer += output
+                if buffer[-1] == '\n':
+                    self._process_output(buffer)
+                    buffer = ''
+            if buffer:
+                self._process_output(buffer)
+            self._cb_results['ansible-playbook_rc'] = rc
             self.logger.debug('ansible-playbook stdout:')
             for ln in proc.stdout:
                 self.logger.debug(ln)
diff --git a/tests/Makefile.am b/tests/Makefile.am
index dc792133..3f1ac9d7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -26,4 +26,5 @@ dist_noinst_SCRIPTS = \
 
 EXTRA_DIST = \
 	answers \
+	ansible_utils_test.py \
 	$(NULL)
diff --git a/tests/ansible_utils_test.py b/tests/ansible_utils_test.py
new file mode 100644
index 00000000..85fc2789
--- /dev/null
+++ b/tests/ansible_utils_test.py
@@ -0,0 +1,198 @@
+#
+# ovirt-hosted-engine-setup -- ovirt hosted engine setup
+# Copyright (C) 2026 oVirt Authors
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+#
+
+"""AnsibleHelper return-code race."""
+
+
+import importlib
+import json
+import logging
+import os
+import sys
+import tempfile
+import types
+
+
+def _src_root():
+    return os.path.abspath(
+        os.path.join(os.path.dirname(__file__), '..', 'src')
+    )
+
+
+def _stub_otopi():
+    if 'otopi.util' in sys.modules and 'otopi.base' in sys.modules:
+        return
+
+    def identity(obj):
+        return obj
+
+    util = types.ModuleType('otopi.util')
+    util.export = identity
+    util.codegen = identity
+
+    class Base(object):
+        def __init__(self):
+            self.logger = logging.getLogger('ansible_utils_test')
+
+    base = types.ModuleType('otopi.base')
+    base.Base = Base
+    otopi = types.ModuleType('otopi')
+    otopi.util = util
+    otopi.base = base
+    sys.modules['otopi'] = otopi
+    sys.modules['otopi.util'] = util
+    sys.modules['otopi.base'] = base
+
+
+def _stub_config():
+    name = 'ovirt_hosted_engine_setup.config'
+    if name in sys.modules:
+        return
+    config = types.ModuleType(name)
+    config.PACKAGE_NAME = 'ovirt-hosted-engine-setup'
+    config.PACKAGE_VERSION = 'test'
+    config.APPLIANCE_RPM_PREFIX = 'ovirt-engine'
+    config.APPLIANCE40_RPM_PREFIX = 'ovirt-engine'
+    config.SYSCONFDIR = '/etc'
+    config.DATADIR = '/usr/share'
+    config.LOCALSTATEDIR = '/var'
+    config.DOCDIR = '/usr/share/doc/ovirt-hosted-engine-setup'
+    sys.modules[name] = config
+
+
+def _prepare_imports():
+    src = _src_root()
+    if src not in sys.path:
+        sys.path.insert(0, src)
+    try:
+        importlib.import_module('otopi.base')
+        importlib.import_module('otopi.util')
+    except ImportError:
+        _stub_otopi()
+    try:
+        importlib.import_module('ovirt_hosted_engine_setup.config')
+    except ImportError:
+        _stub_config()
+
+
+def _modules():
+    _prepare_imports()
+    callback = importlib.import_module('he_ansible.constants')
+    ansible_utils = importlib.import_module(
+        'ovirt_hosted_engine_setup.ansible_utils'
+    )
+    return callback.AnsibleCallback, ansible_utils.AnsibleHelper
+
+
+def _line(callback, kind, body):
+    payload = {
+        callback.TYPE: kind,
+        callback.BODY: body,
+    }
+    return json.dumps(payload) + '\n'
+
+
+def _result_line(callback):
+    body = {
+        'otopi_localvm_dir': {'path': '/var/tmp/localvmtest'},
+    }
+    return _line(callback, callback.RESULT, body)
+
+
+def _recap_line(callback):
+    return _line(
+        callback,
+        callback.DEBUG,
+        'PLAY RECAP [localhost] : ok: 214 failed: 0',
+    )
+
+
+class _Proc(object):
+    def __init__(self, mode):
+        self.mode = mode
+        self.stdout = []
+        self.stderr = []
+        self.returncode = None
+        self.polls = 0
+
+    def poll(self):
+        self.polls += 1
+        if self.mode == 'early':
+            if self.polls < 2:
+                return None
+            self.returncode = 0
+            return 0
+        if self.returncode is None:
+            return None
+        return self.returncode
+
+
+def _run(monkeypatch, mode):
+    callback, helper_cls = _modules()
+    state = {'path': None, 'wrote': False}
+    proc = _Proc(mode)
+    module = sys.modules[
+        'ovirt_hosted_engine_setup.ansible_utils'
+    ]
+    real_mkstemp = tempfile.mkstemp
+
+    def closing_mkstemp():
+        fd, path = real_mkstemp()
+        os.close(fd)
+        return fd, path
+
+    def fake_popen(cmd, env=None, stdout=None, stderr=None):
+        del cmd, stdout, stderr
+        state['path'] = env[callback.OTOPI_CALLBACK_OF]
+        if mode == 'early':
+            with open(state['path'], 'a') as handle:
+                handle.write(_result_line(callback))
+                handle.write(_recap_line(callback))
+        return proc
+
+    def fake_sleep(_seconds):
+        if mode != 'late' or state['wrote']:
+            return
+        with open(state['path'], 'a') as handle:
+            handle.write(_result_line(callback))
+            handle.write(_recap_line(callback))
+        proc.returncode = 0
+        state['wrote'] = True
+
+    monkeypatch.setattr(module.tempfile, 'mkstemp', closing_mkstemp)
+    monkeypatch.setattr(module.subprocess, 'Popen', fake_popen)
+    monkeypatch.setattr(module.time, 'sleep', fake_sleep)
+    helper = helper_cls(raise_on_error=True)
+    return helper.run()
+
+
+def test_result_already_read_keeps_return_code(monkeypatch):
+    result = _run(monkeypatch, 'early')
+    assert result['ansible-playbook_rc'] == 0
+    assert result['otopi_localvm_dir']['path'] == (
+        '/var/tmp/localvmtest'
+    )
+
+
+def test_result_written_during_sleep_keeps_return_code(monkeypatch):
+    result = _run(monkeypatch, 'late')
+    assert result['ansible-playbook_rc'] == 0
+    assert result['otopi_localvm_dir']['path'] == (
+        '/var/tmp/localvmtest'
+    )