diff --git a/src/test_typing_extensions.py b/src/test_typing_extensions.py
index 938f2acc..48107c04 100644
--- a/src/test_typing_extensions.py
+++ b/src/test_typing_extensions.py
@@ -7221,9 +7221,8 @@ def test_alias_names_still_exist(self):
     def test_typing_extensions_compiles_with_opt(self):
         file_path = typing_extensions.__file__
         try:
-            subprocess.check_output(f'{sys.executable} -OO {file_path}',
-                                    stderr=subprocess.STDOUT,
-                                    shell=True)
+            subprocess.check_output([sys.executable, '-OO', file_path],
+                                    stderr=subprocess.STDOUT)
         except subprocess.CalledProcessError:  # pragma: no cover
             self.fail('Module does not compile with optimize=2 (-OO flag).')