diff --git a/CHANGES.md b/CHANGES.md
index 2198803..114165b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,12 @@
 Changelog
 =========
 
+0.13.1
+------
+
+* Fixed import after changes in pip._internal introduced in pip
+  version 18.1
+
 0.13.0
 ------
 
diff --git a/pipdeptree.py b/pipdeptree.py
index 41872ff..8f0ba39 100644
--- a/pipdeptree.py
+++ b/pipdeptree.py
@@ -24,7 +24,7 @@ import pkg_resources
 # from graphviz import backend, Digraph
 
 
-__version__ = '0.13.0'
+__version__ = '0.13.1'
 
 
 flatten = chain.from_iterable