diff --git a/README.md b/README.md
index c7eed13..d5702d1 100644
--- a/README.md
+++ b/README.md
@@ -142,4 +142,4 @@ You can install dependencies these by `pip install -r requirements.txt`
 
 
 ## Acknowledgement
-Thank all contributors ([tats-u](https://github.com/tats-u), [wuaalb](https://github.com/wuaalb), [r9y9](https://github.com/r9y9), [rikrd](https://github.com/rikrd), [kudan2510](https://github.com/kundan2510)) for making this repo better and [sotelo](https://github.com/sotelo) whose [world.py](https://github.com/sotelo/world.py) inspired this repo.<br/>
+Thank all contributors ([tats-u](https://github.com/tats-u), [wuaalb](https://github.com/wuaalb), [r9y9](https://github.com/r9y9), [rikrd](https://github.com/rikrd), [kudan2510](https://github.com/kundan2510), [sabonerune](https://github.com/sabonerune)) for making this repo better and [sotelo](https://github.com/sotelo) whose [world.py](https://github.com/sotelo/world.py) inspired this repo.<br/>
diff --git a/appveyor.yml b/appveyor.yml
index 0fa3ee4..a28d9b9 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -82,6 +82,7 @@ build_script:
   - pip install -e .
 
 test_script:
+  - pip install soundfile matplotlib
   - ps: |
       $ErrorActionPreference = "Stop"
       Set-Location "$env:APPVEYOR_BUILD_FOLDER\demo"
diff --git a/pyworld/__init__.py b/pyworld/__init__.py
index 73ba9e3..d2c1211 100644
--- a/pyworld/__init__.py
+++ b/pyworld/__init__.py
@@ -7,11 +7,13 @@
 
 For more information, see https://github.com/JeremyCCHsu/Python-Wrapper-for-World-Vocoder
 """
-
 from __future__ import division, print_function, absolute_import
-
-import pkg_resources
-
-__version__ = pkg_resources.get_distribution('pyworld').version
+import sys
+if sys.version_info >= (3, 8):
+    from importlib.metadata import version
+    __version__ = version('pyworld')
+else:
+    import pkg_resources
+    __version__ = pkg_resources.get_distribution('pyworld').version
 
 from .pyworld import *
diff --git a/requirements.txt b/requirements.txt
index c397591..679c45a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,2 @@
 numpy
-matplotlib
 argparse; python_version<"3.5"
-soundfile
diff --git a/setup.py b/setup.py
index d60ce23..d3ede1a 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
 from setuptools.command.build_ext import build_ext
 
 
-_VERSION = '0.3.4'
+_VERSION = '0.3.5'
 
 
 world_src_top = join("lib", "World", "src")