diff --git a/src/integrations/weatheralerts.ts b/src/integrations/weatheralerts.ts
index de41453..b0fe980 100644
--- a/src/integrations/weatheralerts.ts
+++ b/src/integrations/weatheralerts.ts
@@ -110,12 +110,12 @@ export default class Weatheralerts implements MeteoalarmIntegration {
 				alertLevel = level;
 				const alertName = fullAlertName.replace(levelName, '').trim();
 				alertType = this.eventTypes[alertName];
-				if(!alertType) {
+				if(alertType == undefined) {
 					throw Error(`Unknown weatheralerts alert type: ${alertName}`);
 				}
 			}
 
-			if(!alertLevel) {
+			if(alertLevel == undefined) {
 				throw Error(`Unknown weatheralerts alert level: ${fullAlertName}`);
 			}