diff --git a/ui/src/pages/AppsTab/AppDeploymentPage/index.tsx b/ui/src/pages/AppsTab/AppDeploymentPage/index.tsx
index 9325042e..127a4476 100644
--- a/ui/src/pages/AppsTab/AppDeploymentPage/index.tsx
+++ b/ui/src/pages/AppsTab/AppDeploymentPage/index.tsx
@@ -321,7 +321,14 @@ export default function AppDeploymentPage() {
     const deployment = deployments.find((d) => d.id === deploymentId);
     if (!deployment) return;
     const snap = deployment.deployedConfigSnapshot;
-    if (!snap) return;
+    if (!snap) {
+      toast({
+        title: 'Cannot restore checkpoint',
+        description: 'This checkpoint predates snapshotting and cannot be restored.',
+        variant: 'warning',
+      });
+      return;
+    }
 
     setForm((prev) => {
       const a = snap.agentConfig ?? {};