diff --git a/libs/nshmp-haz/www/probability-service/probability-usage.model.ts b/libs/nshmp-haz/www/probability-service/probability-usage.model.ts
index 1b2cb1425036fbaed52bc2c057a35aa5e6516f7c..5ae6074e88e884b7821696fd70697134ba05c6df 100644
--- a/libs/nshmp-haz/www/probability-service/probability-usage.model.ts
+++ b/libs/nshmp-haz/www/probability-service/probability-usage.model.ts
@@ -5,5 +5,5 @@ import {RateRequestMetadata} from '../rates-service/rate-usage.model';
 export type ProbabilityUsage = Response<string, ProbabilityRequestMetadata>;
 
 export interface ProbabilityRequestMetadata extends RateRequestMetadata {
-  timespane: DoubleParameter;
+  timespan: DoubleParameter;
 }