diff --git a/aws_lambda_builders/workflows/python_uv/packager.py b/aws_lambda_builders/workflows/python_uv/packager.py
index fc2ef696f..6c616829e 100644
--- a/aws_lambda_builders/workflows/python_uv/packager.py
+++ b/aws_lambda_builders/workflows/python_uv/packager.py
@@ -329,6 +329,7 @@ def _build_from_lock_file(
                 "requirements.txt",
                 "--no-emit-project",  # Don't include the project itself, only dependencies
                 "--no-hashes",  # Skip hashes for cleaner output (optional)
+                "--no-default-groups",  # Exclude PEP 735 default groups (e.g. dev/test) from Lambda zips
                 "--output-file",
                 temp_requirements,
                 # We want to specify the version because `uv export` might default to using a different one
diff --git a/tests/unit/workflows/python_uv/test_packager.py b/tests/unit/workflows/python_uv/test_packager.py
index d370c3f9c..ebe01faa2 100644
--- a/tests/unit/workflows/python_uv/test_packager.py
+++ b/tests/unit/workflows/python_uv/test_packager.py
@@ -242,6 +242,11 @@ def test_build_dependencies_pyproject_with_uv_lock(self):
         # Verify it checked for uv.lock in the right location
         mock_exists.assert_called_with(os.path.join("path", "to", "uv.lock"))
 
+        # Verify export excludes PEP 735 default dependency-groups (dev/test deps
+        # must not land in Lambda zips).
+        export_args = self.mock_uv_runner._uv.run_uv_command.call_args[0][0]
+        self.assertIn("--no-default-groups", export_args)
+
     def test_build_dependencies_pyproject_without_uv_lock(self):
         """Test that pyproject.toml without uv.lock uses standard pyproject build."""
         with (