diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
index 02f6e0c74b5ce8..45c05242537632 100644
--- a/Lib/test/test_regrtest.py
+++ b/Lib/test/test_regrtest.py
@@ -2277,7 +2277,7 @@ def test_python_opts(self):
 
         # Use directly subprocess to control the exact command line
         cmd = [sys.executable,
-               "-m", "test", option,
+               "-E", "-m", "test", option,
                f'--testdir={self.tmptestdir}',
                testname]
         proc = subprocess.run(cmd,
diff --git a/Misc/NEWS.d/next/Tests/2026-05-19-08-10-20.gh-issue-150046.MndDD8.rst b/Misc/NEWS.d/next/Tests/2026-05-19-08-10-20.gh-issue-150046.MndDD8.rst
new file mode 100644
index 00000000000000..b322922e108690
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2026-05-19-08-10-20.gh-issue-150046.MndDD8.rst
@@ -0,0 +1 @@
+Avoid ``PYTHON*`` environment variables affecting regrtest's own tests.