diff --git a/Lib/test/test_pyrepl/test_pyrepl.py b/Lib/test/test_pyrepl/test_pyrepl.py
index 93c80467a04546..7621b8af808f53 100644
--- a/Lib/test/test_pyrepl/test_pyrepl.py
+++ b/Lib/test/test_pyrepl/test_pyrepl.py
@@ -927,8 +927,11 @@ def test_not_wiping_history_file(self):
 
     def run_repl(self, repl_input: str | list[str], env: dict | None = None) -> tuple[str, int]:
         master_fd, slave_fd = pty.openpty()
+        cmd = [sys.executable, "-i", "-u"]
+        if env is None:
+            cmd.append("-I")
         process = subprocess.Popen(
-            [sys.executable, "-i", "-u"],
+            cmd,
             stdin=slave_fd,
             stdout=slave_fd,
             stderr=slave_fd,