diff --git a/src/openfermion/_version.py b/src/openfermion/_version.py
index d7109425..4bbdec0b 100644
--- a/src/openfermion/_version.py
+++ b/src/openfermion/_version.py
@@ -11,4 +11,4 @@
 #   limitations under the License.
 
 """Define version number here and read it from setup.py automatically"""
-__version__ = "1.4.0.dev0"
+__version__ = "1.4.0"