diff --git a/CHANGES.md b/CHANGES.md
index 6b6a807..0b45cc3 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,6 @@
 # Changelog for pymt_heatf
 
-## 3.1 (unreleased)
+## 3.1 (2024-12-17)
 
 - Improve build and CI (#11)
 - Build project with pip (#9)
diff --git a/pyproject.toml b/pyproject.toml
index e862121..5437280 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ requires = ["meson-python", "cython", "numpy", "wheel"]
 [project]
 name = "pymt_heatf"
 description = "PyMT plugin for the HeatModelF model"
-version = "3.1.dev0"
+version = "3.1"
 readme = "README.md"
 authors = [
   {email = "mark.piper@colorado.edu"},