diff --git a/pyproject.toml b/pyproject.toml
index 78d5aebb..680a7574 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,7 +36,7 @@ dependencies = [
 
 [project.optional-dependencies]
 online = [
-    "flask>=2.3,<2.4",
+    "flask>=2.3,<3.1",
     "flask-cors>=3.0,<3.1",
     "panoptes-client>=1.6,<1.7",
     "requests>=2.28,<2.32",