diff --git a/backend/src/hatchling/version/source/env.py b/backend/src/hatchling/version/source/env.py
index b46389437..4d80c6e13 100644
--- a/backend/src/hatchling/version/source/env.py
+++ b/backend/src/hatchling/version/source/env.py
@@ -19,6 +19,9 @@ def get_version_data(self) -> dict:
             raise TypeError(message)
 
         if variable not in os.environ:
+            default = self.config.get('default', '')
+            if default:
+                return {'version': default}
             message = f'environment variable `{variable}` is not set'
             raise RuntimeError(message)
 
diff --git a/tests/backend/version/source/test_env.py b/tests/backend/version/source/test_env.py
index 3e8d74847..a840b634c 100644
--- a/tests/backend/version/source/test_env.py
+++ b/tests/backend/version/source/test_env.py
@@ -27,8 +27,22 @@ def test_variable_not_available(isolation):
         source.get_version_data()
 
 
+def test_variable_not_available_with_default(isolation):
+    source = EnvSource(str(isolation), {'variable': 'ENV_VERSION', 'default': '0.0.0'})
+
+    with EnvVars(exclude=['ENV_VERSION']):
+        assert source.get_version_data()['version'] == '0.0.0'
+
+
 def test_variable_contains_version(isolation):
     source = EnvSource(str(isolation), {'variable': 'ENV_VERSION'})
 
     with EnvVars({'ENV_VERSION': '0.0.1'}):
         assert source.get_version_data()['version'] == '0.0.1'
+
+
+def test_variable_contains_version_with_default(isolation):
+    source = EnvSource(str(isolation), {'variable': 'ENV_VERSION', 'default': '0.0.0'})
+
+    with EnvVars({'ENV_VERSION': '0.0.1'}):
+        assert source.get_version_data()['version'] == '0.0.1'