diff --git a/docs/conf.py b/docs/conf.py
index 6155be6..c337e79 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -28,8 +28,8 @@ project = 'stix2'
 copyright = '2017, OASIS Open'
 author = 'OASIS Open'
 
-version = '0.3.0'
-release = '0.3.0'
+version = '0.4.0'
+release = '0.4.0'
 
 language = None
 exclude_patterns = ['_build', '_templates', 'Thumbs.db', '.DS_Store', 'guide/.ipynb_checkpoints']
diff --git a/setup.cfg b/setup.cfg
index 5edf45c..76162b5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.3.0
+current_version = 0.4.0
 commit = True
 tag = True
 
diff --git a/stix2/version.py b/stix2/version.py
index 493f741..6a9beea 100644
--- a/stix2/version.py
+++ b/stix2/version.py
@@ -1 +1 @@
-__version__ = "0.3.0"
+__version__ = "0.4.0"