diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1c87c9a..f789b1c 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -50,7 +50,7 @@ repos:
         types: [file, yaml]
         entry: yamllint --strict
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: "v0.5.6"
+    rev: "v0.5.7"
     hooks:
       - id: ruff
         args: [--fix, --exit-non-zero-on-fix]
diff --git a/codecov-status.py b/codecov-status.py
index c90e4af..649c7f1 100755
--- a/codecov-status.py
+++ b/codecov-status.py
@@ -45,7 +45,9 @@
             print(data, file=sys.stdout)
             base_cov = 0.0
             head_cov = 0.0
-            updatestamp = datetime.datetime.fromisoformat(data["updatestamp"])
+            updatestamp = start_time
+            if data["updatestamp"]:  # can be None or a string
+                updatestamp = datetime.datetime.fromisoformat(data["updatestamp"])
             if data["base_totals"] is not None:
                 base_cov = data["base_totals"]["coverage"]
             if data["head_totals"] is not None: