diff --git a/src/pymatching/_version.py b/src/pymatching/_version.py
index 46644f45..a1109569 100644
--- a/src/pymatching/_version.py
+++ b/src/pymatching/_version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "0.3.2"
+__version__ = "0.4.0"