diff --git a/lib/ts_utils/utils.py b/lib/ts_utils/utils.py
index 94936cd92057..bf87def015bf 100644
--- a/lib/ts_utils/utils.py
+++ b/lib/ts_utils/utils.py
@@ -35,6 +35,16 @@ def strip_comments(text: str) -> str:
     return text.split("#")[0].strip()
 
 
+def json5_to_json(text: str) -> str:
+    """Incomplete conversion from JSON5-like input to valid JSON."""
+    # Remove full-line // comments only
+    # (Can not remove inline comments)
+    text = re.sub(r"(?m)^\s*//.*\n?", "", text)
+    # Remove trailing commas before } or ]
+    text = re.sub(r",\s*([}\]])", r"\1", text)
+    return text
+
+
 # ====================================================================
 # Printing utilities
 # ====================================================================
diff --git a/pyrightconfig.stricter.json b/pyrightconfig.stricter.json
index c1513a3016ea..7afdcc3eab14 100644
--- a/pyrightconfig.stricter.json
+++ b/pyrightconfig.stricter.json
@@ -9,16 +9,16 @@
         // test cases use a custom pyrightconfig file
         "**/@tests/test_cases",
         "stdlib/__main__.pyi",
+        "stdlib/_tkinter.pyi",
         "stdlib/distutils/cmd.pyi",
         "stdlib/distutils/command",
         "stdlib/distutils/dist.pyi",
         "stdlib/encodings/__init__.pyi",
         "stdlib/lib2to3/fixes/*.pyi",
         "stdlib/numbers.pyi",
-        "stdlib/_tkinter.pyi",
         "stdlib/tkinter/__init__.pyi",
-        "stdlib/tkinter/filedialog.pyi",
         "stdlib/tkinter/dialog.pyi",
+        "stdlib/tkinter/filedialog.pyi",
         "stdlib/tkinter/scrolledtext.pyi",
         "stdlib/tkinter/tix.pyi",
         "stdlib/tkinter/ttk.pyi",
diff --git a/tests/check_typeshed_structure.py b/tests/check_typeshed_structure.py
index a0e905b9974b..dd986b3f3e8b 100755
--- a/tests/check_typeshed_structure.py
+++ b/tests/check_typeshed_structure.py
@@ -7,15 +7,17 @@
 
 from __future__ import annotations
 
+import json
 import os
 import re
 from pathlib import Path
 
 from ts_utils.metadata import read_metadata
-from ts_utils.paths import REQUIREMENTS_PATH, STDLIB_PATH, STUBS_PATH, TEST_CASES_DIR, TESTS_DIR, tests_path
+from ts_utils.paths import PYRIGHT_CONFIG, REQUIREMENTS_PATH, STDLIB_PATH, STUBS_PATH, TEST_CASES_DIR, TESTS_DIR, tests_path
 from ts_utils.utils import (
     get_all_testcase_directories,
     get_gitignore_spec,
+    json5_to_json,
     parse_requirements,
     parse_stdlib_versions_file,
     spec_matches_path,
@@ -173,6 +175,19 @@ def check_requirement_pins() -> None:
         assert str(spec).startswith("=="), msg
 
 
+def check_pyright_exclude_order() -> None:
+    """Check that 'exclude' entries in pyrightconfig.stricter.json are sorted alphabetically."""
+    text = PYRIGHT_CONFIG.read_text(encoding="utf-8")
+    text = json5_to_json(text)
+    data = json.loads(text)
+    exclude: list[str] = data.get("exclude", [])
+
+    for i in range(len(exclude) - 1):
+        assert (
+            exclude[i].lower() <= exclude[i + 1].lower()
+        ), f"Entry '{exclude[i]}' should come before '{exclude[i + 1]}' in the {PYRIGHT_CONFIG.name} exclude list"
+
+
 if __name__ == "__main__":
     check_versions_file()
     check_metadata()
@@ -182,3 +197,4 @@ def check_requirement_pins() -> None:
     check_stubs()
     check_distutils()
     check_test_cases()
+    check_pyright_exclude_order()