diff --git a/main.py b/main.py
index 0f30997..d2d4359 100644
--- a/main.py
+++ b/main.py
@@ -541,8 +541,8 @@ async def main(
     ]:
         comma_separated_list = ','.join(l)
 
-        with open(os.environ['GITHUB_ENV'], 'a') as f:
-            f.write(f'{name}={comma_separated_list}')
+        with open(os.environ['GITHUB_OUTPUT'], 'a') as f:
+            f.write(f'{name}={comma_separated_list}\n')
 
 
 if __name__ == '__main__':
diff --git a/main_tests.py b/main_tests.py
index 67bb79a..da364df 100644
--- a/main_tests.py
+++ b/main_tests.py
@@ -55,12 +55,12 @@ def http_client(ok_response):
 
 
 @pytest.fixture(autouse=True)
-def github_env():
+def github_output():
     """
-    Create a GITHUB_ENV env value to mock the Github actions equivalent.
+    Create a GITHUB_OUTPUT env value to mock the Github actions equivalent.
     """
     with tempfile.NamedTemporaryFile() as temp:
-        os.environ['GITHUB_ENV'] = temp.name
+        os.environ['GITHUB_OUTPUT'] = temp.name
         yield
 
 
@@ -589,12 +589,12 @@ async def test_outputs_are_set(mocker):
             'token': 'test',
         }
     )
-    with open(os.environ['GITHUB_ENV']) as f:
-        env_vars = f.readlines()[0]
+    with open(os.environ['GITHUB_OUTPUT']) as f:
+        out_vars = f.read()
 
     for i in [
         'needs-github-assistance=',
         'deleted=',
         'failed=',
     ]:
-        assert i in env_vars
+        assert i in out_vars