diff --git a/python/helpers/tests/__main__.py b/python/helpers/tests/__main__.py
index b0d976f8a924..f307df515c84 100644
--- a/python/helpers/tests/__main__.py
+++ b/python/helpers/tests/__main__.py
@@ -21,7 +21,7 @@ def get_test_runner():
     try:
         import teamcity.unittestpy
         if teamcity.is_running_under_teamcity():
-            return teamcity.unittestpy.TeamcityTestRunner()
+            return teamcity.unittestpy.TeamcityTestRunner(buffer=True)
     except ImportError:
         pass
     return unittest.TextTestRunner()
diff --git a/python/helpers/tests/generator3_tests/__init__.py b/python/helpers/tests/generator3_tests/__init__.py
index e596a7c6a7c7..95f37b7ce9e8 100644
--- a/python/helpers/tests/generator3_tests/__init__.py
+++ b/python/helpers/tests/generator3_tests/__init__.py
@@ -1,9 +1,11 @@
-from contextlib import contextmanager
-from io import open
+import logging
 import os
 import shutil
+import sys
 import tempfile
 import unittest
+from contextlib import contextmanager
+from io import open
 
 _test_dir = os.path.dirname(__file__)
 _test_data_root_dir = os.path.join(_test_dir, 'data')
@@ -13,6 +15,23 @@ _override_test_data = False
 class GeneratorTestCase(unittest.TestCase):
     longMessage = True
 
+    @classmethod
+    def setUpClass(cls):
+        super(GeneratorTestCase, cls).setUpClass()
+        # Logger cannot be initialized beforehand (say, on top-level), because,
+        # otherwise, it won't take into account buffered sys.stderr needed by
+        # teamcity-messages
+        cls.log = logging.getLogger(cls.__name__)
+        handler = logging.StreamHandler(sys.stderr)
+        handler.setFormatter(logging.Formatter(fmt='%(levelname)s:%(name)s:%(message)s'))
+        cls.log.addHandler(handler)
+        cls.log.setLevel(logging.DEBUG)
+
+    @classmethod
+    def tearDownClass(cls):
+        delattr(cls, 'log')
+        super(GeneratorTestCase, cls).tearDownClass()
+
     def setUp(self):
         self.temp_dir = tempfile.mkdtemp(prefix='{}_{}__'.format(self.test_class_name, self.test_name))
 
diff --git a/python/helpers/tests/generator3_tests/test_generation.py b/python/helpers/tests/generator3_tests/test_generation.py
index 03f7ab206d68..b0b3f4e9e76f 100644
--- a/python/helpers/tests/generator3_tests/test_generation.py
+++ b/python/helpers/tests/generator3_tests/test_generation.py
@@ -1,4 +1,3 @@
-import logging
 import os
 import subprocess
 import sys
@@ -7,6 +6,7 @@ import unittest
 
 import generator3
 import six
+from generator3_tests import GeneratorTestCase
 from pycharm_generator_utils.constants import (
     ENV_TEST_MODE_FLAG,
     ENV_VERSION,
@@ -14,15 +14,11 @@ from pycharm_generator_utils.constants import (
     CACHE_DIR_NAME,
     ENV_STANDALONE_MODE_FLAG,
 )
-from generator3_tests import GeneratorTestCase
-
-logging.basicConfig(level=logging.DEBUG)
 
 # Such version implies that skeletons are always regenerated
 TEST_GENERATOR_VERSION = '1000.0'
 
 _run_generator_in_separate_process = True
-_log = logging.getLogger(__name__)
 
 
 class SkeletonCachingTest(GeneratorTestCase):
@@ -73,8 +69,13 @@ class SkeletonCachingTest(GeneratorTestCase):
                 if mod_path:
                     args.append(mod_path)
 
-            _log.info('Launching generator3 as: ' + ' '.join(args))
-            subprocess.call(args, env=env)
+            self.log.info('Launching generator3 as: ' + ' '.join(args))
+            process = subprocess.Popen(args, env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            process.wait()
+            sys.stdout.write(process.stdout.read().decode('utf-8'))
+            process.stdout.close()
+            sys.stderr.write(process.stderr.read().decode('utf-8'))
+            process.stderr.close()
         else:
             os.environ.update(env)
             sys.path.append(extra_syspath_entry)
@@ -85,7 +86,7 @@ class SkeletonCachingTest(GeneratorTestCase):
                 else:
                     generator3.process_one(mod_qname, mod_path, mod_qname in sys.builtin_module_names, output_dir)
             except Exception:
-                _log.error('Raised inside generator', exc_info=True)
+                self.log.error('Raised inside generator', exc_info=True)
             finally:
                 if mod_qname != 'sys':
                     sys.modules.pop(mod_qname, None)