diff --git a/deployment.py b/deployment.py
index 6b31803..5602ceb 100644
--- a/deployment.py
+++ b/deployment.py
@@ -19,7 +19,7 @@ def run():
     while True:
         pass
 
-    with open(os.environ['GITHUB_OUTPUT'], 'a') as gh_output:
+    with open(os.environ['GITHUB_OUTPUT'], 'a+') as gh_output:
         print(f'lastNumber={last_number}', file=gh_output)