diff --git a/docs/source/conf.py b/docs/source/conf.py
index dd37f72599..2410a887db 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -81,7 +81,7 @@ copyright = '2011-2020, Massachusetts Institute of Technology and OpenMC contrib
 # The short X.Y version.
 version = "0.12"
 # The full version, including alpha/beta/rc tags.
-release = "0.12.0"
+release = "0.12.1-dev"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/include/openmc/constants.h b/include/openmc/constants.h
index 2da096c612..13b62ee87d 100644
--- a/include/openmc/constants.h
+++ b/include/openmc/constants.h
@@ -21,8 +21,8 @@ using double_4dvec = std::vector<std::vector<std::vector<std::vector<double>>>>;
 // OpenMC major, minor, and release numbers
 constexpr int VERSION_MAJOR {0};
 constexpr int VERSION_MINOR {12};
-constexpr int VERSION_RELEASE {0};
-constexpr bool VERSION_DEV {false};
+constexpr int VERSION_RELEASE {1};
+constexpr bool VERSION_DEV {true};
 constexpr std::array<int, 3> VERSION {VERSION_MAJOR, VERSION_MINOR, VERSION_RELEASE};
 
 // HDF5 data format
diff --git a/openmc/__init__.py b/openmc/__init__.py
index 13edd1c767..3e66c54115 100644
--- a/openmc/__init__.py
+++ b/openmc/__init__.py
@@ -34,4 +34,4 @@ from . import examples
 # Import a few convencience functions that used to be here
 from openmc.model import rectangular_prism, hexagonal_prism
 
-__version__ = '0.12.0'
+__version__ = '0.12.1-dev'