diff --git a/CHANGELOG b/CHANGELOG
index 7264c9b..f53813c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,12 @@
+v1.6.6
+  Version 1.6.6
+
+  Bugfix release
+
+  - Warn when constructing BatchHttpRequest using the legacy batch URI (#488)
+  - Increase the default media chunksize to 100MB. (#482)
+  - Remove unnecessary parsing of mime headers in HttpRequest.__init__ (#467)
+
 v1.6.5
   Version 1.6.5
 
diff --git a/googleapiclient/__init__.py b/googleapiclient/__init__.py
index 0cbe2c3..b3b6527 100644
--- a/googleapiclient/__init__.py
+++ b/googleapiclient/__init__.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "1.6.5"
+__version__ = "1.6.6"
 
 # Set default logging handler to avoid "No handler found" warnings.
 import logging