diff --git a/README.md b/README.md
index 442357c..ddd2843 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # Anomaly Detection Toolkit (ADTK)
 
 [![Build Status](https://travis-ci.com/arundo/adtk.svg?branch=master)](https://travis-ci.com/arundo/adtk)
-[![Docs](https://readthedocs.com/projects/arundo-adtk/badge/?version=stable)](https://arundo-adtk.readthedocs-hosted.com)
+[![Documentation Status](https://readthedocs.org/projects/adtk/badge/?version=stable)](https://adtk.readthedocs.io/en/stable)
 [![Coverage Status](https://coveralls.io/repos/github/arundo/adtk/badge.svg?branch=master&service=github)](https://coveralls.io/github/arundo/adtk?branch=master)
 [![PyPI](https://img.shields.io/pypi/v/adtk)](https://pypi.org/project/adtk/)
 [![Downloads](https://pepy.tech/badge/adtk)](https://pepy.tech/project/adtk)
@@ -22,7 +22,7 @@ with unified APIs, as well as pipe classes that connect them together into
 models. It also provides some functions to process and visualize time series
 and anomaly events.
 
-See https://arundo-adtk.readthedocs-hosted.com for complete documentation.
+See https://adtk.readthedocs.io for complete documentation.
 
 ## Installation
 
@@ -45,10 +45,10 @@ pip install ./
 
 ## Examples
 
-Please see [Quick Start](https://arundo-adtk.readthedocs-hosted.com/en/stable/quickstart.html) for a simple example.
+Please see [Quick Start](https://adtk.readthedocs.io/en/stable/quickstart.html) for a simple example.
 
 For more detailed examples of each module of ADTK, please refer to
-[Examples](https://arundo-adtk.readthedocs-hosted.com/en/stable/examples.html)
+[Examples](https://adtk.readthedocs.io/en/stable/examples.html)
 section in the documentation or [an interactive demo notebook](https://mybinder.org/v2/gh/arundo/adtk/master?filepath=docs%2Fnotebooks%2Fdemo.ipynb).
 
 ## Contributing
@@ -58,7 +58,7 @@ discuss what you would like to change.
 
 Please make sure to update unit tests as appropriate.
 
-Please see [Contributing](https://arundo-adtk.readthedocs-hosted.com/en/stable/developer.html) for more details.
+Please see [Contributing](https://adtk.readthedocs.io/en/stable/developer.html) for more details.
 
 
 ## License
diff --git a/docs/conf.py b/docs/conf.py
index c3a421c..4d81838 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -70,7 +70,7 @@
 # The short X.Y version.
 version = "0.6"
 # The full version, including alpha/beta/rc tags.
-release = "0.6.0"
+release = "0.6.2"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/docs/releasehistory.rst b/docs/releasehistory.rst
index 7eb7c5d..d176c7a 100644
--- a/docs/releasehistory.rst
+++ b/docs/releasehistory.rst
@@ -2,12 +2,22 @@
 Release History
 ***************
 
+Version 0.6.2 (Apr 16, 2020)
+===================================
+- Hot fix of wrong documentation url
+
+Version 0.6.1 (Apr 16, 2020)
+===================================
+- Migrated the documentation to a new host
+- Fixed minor typos in the documentation
+- Fixed a minor type hinting bug
+
 Version 0.6.0 (Mar 10, 2020)
 ===================================
 - Re-designed the API of :py:mod:`adtk.visualization.plot`
 - Removed :py:mod:`adtk.data.resample` because its functionality is highly overlapped with pandas resampler module
-- Made :py:mod:`adtk.data.expand_event` accept events in the form of pandas Series/DataFrame
-- Made :py:mod:`adtk.data.expand_event` accept time delta in the form of `str` or `int`
+- Made :py:mod:`adtk.data.expand_events` accept events in the form of pandas Series/DataFrame
+- Made :py:mod:`adtk.data.expand_events` accept time delta in the form of `str` or `int`
 - Changed the output type of :py:mod:`adtk.data.split_train_test` from a 2-tuple of lists to a list of 2-tuples
 - Turned the following model parameters required from optional
 
diff --git a/setup.cfg b/setup.cfg
index ac720db..6ca21be 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = adtk
-version = 0.6.0
+version = 0.6.2
 author = Arundo Analytics, Inc.
 maintainer = Tailai Wen
 maintainer_email = tailai.wen@arundo.com
@@ -53,7 +53,7 @@ test =
     coveralls>=1.7
     mypy>=0.641
 doc =
-    sphinx>=2.0
+    sphinx>=2.4,<3
     sphinx_rtd_theme<0.5
     nbsphinx>=0.4
     python-dateutil>=2.5
diff --git a/src/adtk/__init__.py b/src/adtk/__init__.py
index 99424dd..f079c9d 100644
--- a/src/adtk/__init__.py
+++ b/src/adtk/__init__.py
@@ -16,8 +16,8 @@
 models. It also provides some functions to process and visualize time series
 and anomaly events.
 
-See https://arundo-adtk.readthedocs-hosted.com for complete documentation.
+See https://adtk.readthedocs.io for complete documentation.
 
 """
 
-__version__ = "0.6.0"
+__version__ = "0.6.2"
diff --git a/src/adtk/detector/_detector_hd.py b/src/adtk/detector/_detector_hd.py
index 0afe35e..85ca06a 100644
--- a/src/adtk/detector/_detector_hd.py
+++ b/src/adtk/detector/_detector_hd.py
@@ -126,7 +126,7 @@ def _fit_core(self, df: pd.DataFrame) -> None:
         if df.dropna().empty:
             raise RuntimeError("Valid values are not enough for training.")
         clustering_result = self.model.fit_predict(df.dropna())
-        cluster_count = Counter(clustering_result)
+        cluster_count = Counter(clustering_result)  # type: Counter
         self._anomalous_cluster_id = cluster_count.most_common()[-1][0]
 
     def _predict_core(self, df: pd.DataFrame) -> pd.Series: