diff --git a/appveyor.yml b/appveyor.yml
index 9e2100953..4e6f5b222 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,15 +1,37 @@
+# Use unofficial Windows Binaries for Python Extension Packages from
+# https://www.lfd.uci.edu/~gohlke/pythonlibs/
+
 build: off
 
 environment:
   matrix:
+#    - PYTHON: "C:/Python36"
+#      PYTHON_VERSION: "3.6"
+#      PYTHON_ARCH: "32"
+#      ARTAGGER_PKG: "https://github.com/wannaphongcom/artagger/tarball/master#egg=artagger"
+#      PYICU_PKG: "https://www.dropbox.com/s/pahorbq29y9cura/PyICU-2.3.1-cp36-cp36m-win32.whl?dl=1"
+
     - PYTHON: "C:/Python36-x64"
       PYTHON_VERSION: "3.6"
       PYTHON_ARCH: "64"
       ARTAGGER_PKG: "https://github.com/wannaphongcom/artagger/tarball/master#egg=artagger"
+      PYICU_PKG: "https://www.dropbox.com/s/7t0rrxwckqbgivi/PyICU-2.3.1-cp36-cp36m-win_amd64.whl?dl=1"
+
+#    - PYTHON: "C:/Python37"
+#      PYTHON_VERSION: "3.7"
+#      PYTHON_ARCH: "32"
+#      ARTAGGER_PKG: "https://github.com/wannaphongcom/artagger/tarball/master#egg=artagger"
+#      PYICU_PKG: "https://www.dropbox.com/s/3xwdnwhdcu619x4/PyICU-2.3.1-cp37-cp37m-win32.whl?dl=1"
+
+    - PYTHON: "C:/Python37-x64"
+      PYTHON_VERSION: "3.7"
+      PYTHON_ARCH: "64"
+      ARTAGGER_PKG: "https://github.com/wannaphongcom/artagger/tarball/master#egg=artagger"
+      PYICU_PKG: "https://www.dropbox.com/s/le5dckc3231opqt/PyICU-2.3.1-cp37-cp37m-win_amd64.whl?dl=1"
 
 init:
   - "ECHO %PYTHON% %PYTHON_VERSION% %PYTHON_ARCH%"  
-  - ps: "ls C:/Python*"
+#  - ps: "ls C:/Python*"
 
 install:
   - "chcp 65001"
@@ -19,10 +41,10 @@ install:
   - "%PYTHON%/python.exe -m pip install --upgrade pip"
   - "%PYTHON%/python.exe -m pip install coveralls[yaml]"
   - "%PYTHON%/python.exe -m pip install coverage"
-  - "%PYTHON%/python.exe -m pip install https://www.dropbox.com/s/g84479l8yhv5ohi/PyICU-2.2-cp36-cp36m-win_amd64.whl?dl=1"
+  - "%PYTHON%/python.exe -m pip install %PYICU_PKG%"
   - "%PYTHON%/python.exe -m pip install %ARTAGGER_PKG%"
   - "%PYTHON%/python.exe -m pip install -e .[artagger,icu,ipa,ner,thai2fit,deepcut]"
 
 test_script:
   - "%PYTHON%/python.exe -m pip --version"
-  - "%PYTHON%/python.exe -m coverage run --source=pythainlp setup.py test"
\ No newline at end of file
+  - "%PYTHON%/python.exe -m coverage run --source=pythainlp setup.py test"
diff --git a/pythainlp/corpus/__init__.py b/pythainlp/corpus/__init__.py
index 46e557546..036dbf9d7 100644
--- a/pythainlp/corpus/__init__.py
+++ b/pythainlp/corpus/__init__.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 import os
+from typing import NoReturn, Union
 from urllib.request import urlopen
 
 import requests
@@ -14,9 +15,9 @@
 _CORPUS_PATH = os.path.join(get_pythainlp_path(), _CORPUS_DIRNAME)
 
 _CORPUS_DB_URL = (
-    "https://raw.githubusercontent.com/" +
-    "PyThaiNLP/pythainlp-corpus/" +
-    "master/db.json"
+    "https://raw.githubusercontent.com/"
+    + "PyThaiNLP/pythainlp-corpus/"
+    + "master/db.json"
 )
 
 _CORPUS_DB_FILENAME = "db.json"
@@ -51,7 +52,7 @@ def get_corpus(filename: str) -> frozenset:
     return frozenset(lines)
 
 
-def get_corpus_path(name: str) -> [str, None]:
+def get_corpus_path(name: str) -> Union[str, None]:
     """
     Get corpus path
 
@@ -72,18 +73,21 @@ def get_corpus_path(name: str) -> [str, None]:
     return None
 
 
-def _download(url: str, dst: str):
+def _download(url: str, dst: str) -> int:
     """
     @param: url to download file
     @param: dst place to put the file
     """
     file_size = int(urlopen(url).info().get("Content-Length", -1))
+
     if os.path.exists(dst):
         first_byte = os.path.getsize(dst)
     else:
         first_byte = 0
+
     if first_byte >= file_size:
         return file_size
+
     header = {"Range": "bytes=%s-%s" % (first_byte, file_size)}
     pbar = tqdm(
         total=file_size,
@@ -99,10 +103,11 @@ def _download(url: str, dst: str):
                 f.write(chunk)
                 pbar.update(1024)
     pbar.close()
-    # return file_size
 
+    return file_size
 
-def download(name: str, force: bool = False):
+
+def download(name: str, force: bool = False) -> NoReturn:
     """
     Download corpus
 
@@ -113,6 +118,7 @@ def download(name: str, force: bool = False):
     temp = Query()
     data = requests.get(corpus_db_url())
     data_json = data.json()
+
     if name in list(data_json.keys()):
         temp_name = data_json[name]
         print("Download:", name)
diff --git a/pythainlp/corpus/tnc.py b/pythainlp/corpus/tnc.py
index 651e704a1..4ce7a3337 100644
--- a/pythainlp/corpus/tnc.py
+++ b/pythainlp/corpus/tnc.py
@@ -48,7 +48,7 @@ def word_freq(word: str, domain: str = "all") -> int:
 
     r = requests.post(url, data=data)
 
-    pat = re.compile(r'TOTAL</font>(?s).*?#ffffff">(.*?)</font>')
+    pat = re.compile(r'TOTAL</font>.*?#ffffff">(.*?)</font>', flags=re.DOTALL)
     match = pat.search(r.text)
 
     n = 0
diff --git a/pythainlp/spell/pn.py b/pythainlp/spell/pn.py
index 2d509cb15..eccbb27d1 100644
--- a/pythainlp/spell/pn.py
+++ b/pythainlp/spell/pn.py
@@ -34,7 +34,7 @@ def _keep(
     min_len: int,
     max_len: int,
     dict_filter: Callable[[str], bool],
-):
+) -> Callable[[str], bool]:
     """
     Keep only Thai words with at least min_freq frequency
     and has length between min_len and max_len characters
diff --git a/tests/__init__.py b/tests/__init__.py
index 4ffcaf2c8..1c2e217d0 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -577,6 +577,7 @@ def test_thai_strftime(self):
             thai_strftime(date, "%Aที่ %d %B พ.ศ. %Y เวลา %H:%Mน. (%a %d-%b-%y) %% %"),
             "วันพุธที่ 06 ตุลาคม พ.ศ. 2519 เวลา 01:40น. (พ 06-ต.ค.-19) % %",
         )
+        self.assertIsNotNone(thai_strftime(date, "%A%a%B%b%C%c%D%F%G%g%v%X%x%Y%y%+"))
 
     # ### pythainlp.util.normalize