diff --git a/web/src/TacComponents.tsx b/web/src/TacComponents.tsx
index 098b4c6..b4b3297 100644
--- a/web/src/TacComponents.tsx
+++ b/web/src/TacComponents.tsx
@@ -570,7 +570,7 @@ export function OverTemperatureNotification() {
     <Alert
       statusIconAriaLabel="Warning"
       type="warning"
-      visible={warning !== null && warning !== "Okay"}
+      visible={warning !== undefined && warning !== "Okay"}
       header="Your LXA TAC is overheating"
     >
       The LXA TAC's temperature is{" "}
@@ -608,7 +608,7 @@ export function UsbOverloadNotification() {
     <Alert
       statusIconAriaLabel="Warning"
       type="warning"
-      visible={overload !== null}
+      visible={overload !== undefined && overload !== null}
       header={header}
     >
       Disconnect {detail} or use a powered hub to resolve this issue.