diff --git a/doc/src/conf.py b/doc/src/conf.py
index 95efc32..ff60f99 100644
--- a/doc/src/conf.py
+++ b/doc/src/conf.py
@@ -42,7 +42,7 @@ author = 'Oracle'
 # The short X.Y version.
 version = '6.4'
 # The full version, including alpha/beta/rc tags.
-release = '6.4.0'
+release = '6.4.1'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
diff --git a/doc/src/releasenotes.rst b/doc/src/releasenotes.rst
index 08bb790..500f913 100644
--- a/doc/src/releasenotes.rst
+++ b/doc/src/releasenotes.rst
@@ -8,6 +8,24 @@ cx_Oracle Release Notes
 
 .. _releasenotes60:
 
+Version 6.4.1 (July 2018)
+-------------------------
+
+#)  Update to `ODPI-C 2.4.2
+    <https://oracle.github.io/odpi/doc/releasenotes.html#
+    version-2-4-2-july-9-2018>`__.
+
+    - Avoid buffer overrun due to improper calculation of length byte when
+      converting some negative 39 digit numbers from string to the internal
+      Oracle number format
+      (`ODPI-C issue 67 <https://github.com/oracle/odpi/issues/67>`__).
+
+#)  Prevent error "cx_Oracle.ProgrammingError: positional and named binds
+    cannot be intermixed" when calling cursor.setinputsizes() without any
+    parameters and then calling cursor.execute() with named bind parameters
+    (`issue 199 <https://github.com/oracle/python-cx_Oracle/issues/199>`__).
+
+
 Version 6.4 (July 2018)
 -----------------------
 
diff --git a/setup.py b/setup.py
index 4340e3f..c7b3a9f 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@ except:
     from distutils.extension import Extension
 
 # define build constants
-BUILD_VERSION = "6.4"
+BUILD_VERSION = "6.4.1"
 
 # setup extra link and compile args
 extraLinkArgs = []