diff --git a/py_ballisticcalc.exts/pyproject.toml b/py_ballisticcalc.exts/pyproject.toml
index 9687887..7105e16 100644
--- a/py_ballisticcalc.exts/pyproject.toml
+++ b/py_ballisticcalc.exts/pyproject.toml
@@ -8,7 +8,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "py_ballisticcalc.exts"
-version = "2.1.0a3"
+version = "2.1.0a4"
 
 authors = [
     { name="o-murphy", email="thehelixpg@gmail.com" },
diff --git a/pyproject.toml b/pyproject.toml
index 23d97db..587e691 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "py_ballisticcalc"
-version = "2.1.0a3"
+version = "2.1.0a4"
 
 authors = [
     { name="o-murphy", email="thehelixpg@gmail.com" },
@@ -50,7 +50,7 @@ include = ["py_ballisticcalc*"]
 
 
 [project.optional-dependencies]
-exts = ['py_ballisticcalc.exts==2.1.0a3']
+exts = ['py_ballisticcalc.exts==2.1.0a4']
 charts = ['matplotlib', 'pandas']
 visualize = ['matplotlib', 'pandas']
 dev = [