diff --git a/news/6072.bugfix.rst b/news/6072.bugfix.rst
new file mode 100644
index 00000000..a6210034
--- /dev/null
+++ b/news/6072.bugfix.rst
@@ -0,0 +1 @@
+Remove logic that treats ``CI`` variable to use ``do_run_nt`` shell logic, as the original reasons for that patch were no longer valid.
diff --git a/pipenv/routines/shell.py b/pipenv/routines/shell.py
index a4a4df62..1e8b286b 100644
--- a/pipenv/routines/shell.py
+++ b/pipenv/routines/shell.py
@@ -3,7 +3,6 @@ import subprocess
 import sys
 from os.path import expandvars
 
-from pipenv import environments
 from pipenv.utils.project import ensure_project
 from pipenv.utils.shell import cmd_list_to_shell, system_which
 from pipenv.vendor import click
@@ -99,9 +98,7 @@ def do_run(project, command, args, python=False, pypi_mirror=None):
         click.echo("Can't run script {0!r}-it's empty?", err=True)
     run_args = [project, script]
     run_kwargs = {"env": env}
-    # We're using `do_run_nt` on CI (even if we're running on a non-nt machine)
-    # as a workaround for https://github.com/pypa/pipenv/issues/4909.
-    if os.name == "nt" or environments.PIPENV_IS_CI:
+    if os.name == "nt":
         run_fn = do_run_nt
     else:
         run_fn = do_run_posix
diff --git a/tests/conftest.py b/tests/conftest.py
index 13778403..fc75b6b5 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,14 +1,4 @@
 import pytest
-import os
-
-# Note that we have to do this *before* `pipenv.environments` gets imported,
-# which is why we're doing it here as a side effect of importing this module.
-# CI=1 is necessary as a workaround for https://github.com/pypa/pipenv/issues/4909
-os.environ['CI'] = '1'
-
-def pytest_sessionstart(session):
-    import pipenv.environments
-    assert pipenv.environments.PIPENV_IS_CI
 
 
 @pytest.fixture()
diff --git a/tests/integration/test_run.py b/tests/integration/test_run.py
index 0cb99d81..2b938aa9 100644
--- a/tests/integration/test_run.py
+++ b/tests/integration/test_run.py
@@ -41,8 +41,8 @@ multicommand = "bash -c \"cd docs && make html\""
         c = p.pipenv('run notfoundscript')
         assert c.returncode != 0
         assert c.stdout == ''
-        if os.name != 'nt':     # TODO: Implement this message for Windows.
-            assert 'not found' in c.stderr
+        if os.name != 'nt':
+            assert 'could not be found' in c.stderr
 
         project = Project()