diff --git a/python/helpers/pycharm/_jb_nosetest_runner.py b/python/helpers/pycharm/_jb_nosetest_runner.py
index 51e318fc27d4..994e6bff37ee 100644
--- a/python/helpers/pycharm/_jb_nosetest_runner.py
+++ b/python/helpers/pycharm/_jb_nosetest_runner.py
@@ -4,12 +4,14 @@ import re
 import nose
 import sys
 
-from _jb_runner_tools import jb_start_tests, jb_patch_separator, jb_doc_args
+from _jb_runner_tools import jb_start_tests, jb_patch_separator, jb_doc_args, JB_DISABLE_BUFFERING
 from teamcity.nose_report import TeamcityReport
 
 if __name__ == '__main__':
     path, targets, additional_args = jb_start_tests()
     sys.argv += [path] if path else jb_patch_separator(targets, fs_glue="/", python_glue=".", fs_to_python_glue=".py:")
     sys.argv += additional_args
+    if JB_DISABLE_BUFFERING and "-s" not in sys.argv:
+        sys.argv += ["-s"]
     jb_doc_args("Nosetest", sys.argv)
     nose.main(addplugins=[TeamcityReport()])
diff --git a/python/helpers/pycharm/_jb_pytest_runner.py b/python/helpers/pycharm/_jb_pytest_runner.py
index 18ca4cd3030b..61f657f356c7 100644
--- a/python/helpers/pycharm/_jb_pytest_runner.py
+++ b/python/helpers/pycharm/_jb_pytest_runner.py
@@ -5,7 +5,7 @@ import sys
 import pytest
 from _pytest.config import get_plugin_manager
 
-from _jb_runner_tools import jb_start_tests, jb_patch_separator, jb_doc_args
+from _jb_runner_tools import jb_start_tests, jb_patch_separator, jb_doc_args, JB_DISABLE_BUFFERING
 from teamcity import pytest_plugin
 
 
@@ -17,11 +17,15 @@ if __name__ == '__main__':
     # When file is launched in py.test it should be file.py: you can't provide it as bare module
     joined_targets = [t + ".py" if ":" not in t else t for t in joined_targets]
     sys.argv += [path] if path else joined_targets
-    jb_doc_args("py.test", sys.argv[1:])
 
     # plugin is discovered automatically in 3, but not in 2
     # to prevent "plugin already registered" problem we check it first
     plugins_to_load = []
     if not get_plugin_manager().hasplugin("pytest-teamcity"):
         plugins_to_load.append(pytest_plugin)
-    pytest.main(sys.argv[1:], plugins_to_load)
+
+    args = sys.argv[1:]
+    if JB_DISABLE_BUFFERING and "-s" not in args:
+        args += ["-s"]
+    jb_doc_args("py.test", args)
+    pytest.main(args, plugins_to_load)
diff --git a/python/helpers/pycharm/_jb_runner_tools.py b/python/helpers/pycharm/_jb_runner_tools.py
index 82a396bc586e..7bff640d5beb 100644
--- a/python/helpers/pycharm/_jb_runner_tools.py
+++ b/python/helpers/pycharm/_jb_runner_tools.py
@@ -14,6 +14,11 @@ from teamcity import teamcity_presence_env_var, messages
 if teamcity_presence_env_var not in os.environ:
     os.environ[teamcity_presence_env_var] = "LOCAL"
 
+# Providing this env variable disables output buffering.
+# anything sent to stdout/stderr goes to IDE directly, not after test is over like it is done by default.
+# out and err are not in sync, so output may go to wrong test
+JB_DISABLE_BUFFERING = "JB_DISABLE_BUFFERING" in os.environ
+
 
 def _parse_parametrized(part):
     """
diff --git a/python/helpers/pycharm/_jb_unittest_runner.py b/python/helpers/pycharm/_jb_unittest_runner.py
index 9ca46b4d00c8..369b434329e1 100644
--- a/python/helpers/pycharm/_jb_unittest_runner.py
+++ b/python/helpers/pycharm/_jb_unittest_runner.py
@@ -3,7 +3,7 @@ import os
 import sys
 from unittest import main
 
-from _jb_runner_tools import jb_start_tests, jb_doc_args
+from _jb_runner_tools import jb_start_tests, jb_doc_args, JB_DISABLE_BUFFERING
 from teamcity import unittestpy
 
 if __name__ == '__main__':
@@ -32,4 +32,4 @@ if __name__ == '__main__':
     jb_doc_args("unittests", args)
     # Working dir should be on path, that is how unittest work when launched from command line
     sys.path.append(os.getcwd())
-    main(argv=args, module=None, testRunner=unittestpy.TeamcityTestRunner, buffer=True)
+    main(argv=args, module=None, testRunner=unittestpy.TeamcityTestRunner, buffer=not JB_DISABLE_BUFFERING)