diff --git a/.bumpversion.cfg b/.bumpversion.cfg
index 31b973a823..3048e8d820 100644
--- a/.bumpversion.cfg
+++ b/.bumpversion.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.3.4
+current_version = 0.4.0
 commit = True
 tag = True
 
diff --git a/setup.py b/setup.py
index 45c4270f01..7057b5c30b 100644
--- a/setup.py
+++ b/setup.py
@@ -75,7 +75,7 @@
 
 setup(
     name='pyhf',
-    version='0.3.4',
+    version='0.4.0',
     description='(partial) pure python histfactory implementation',
     long_description=long_description,
     long_description_content_type='text/markdown',
diff --git a/src/pyhf/version.py b/src/pyhf/version.py
index 9947f15ec1..5b00c98f23 100644
--- a/src/pyhf/version.py
+++ b/src/pyhf/version.py
@@ -2,4 +2,4 @@
 
 # Use semantic versioning (https://semver.org/)
 # The version number is controlled through bumpversion.cfg
-__version__ = '0.3.4'
+__version__ = '0.4.0'