diff --git a/src/lib/services/generic.service.ts b/src/lib/services/generic.service.ts
index f896233..d29986b 100644
--- a/src/lib/services/generic.service.ts
+++ b/src/lib/services/generic.service.ts
@@ -99,7 +99,9 @@ export abstract class GenericService<I> {
     protected _queryParams(queryParams?: List<QueryParam>): HttpParams {
         let queryParameters = new HttpParams({ encoder: new CustomHttpUrlEncodingCodec() });
         queryParams?.forEach(param => {
-            queryParameters = queryParameters.append(param.key, param.value);
+            if (param.value) {
+                queryParameters = queryParameters.append(param.key, param.value);
+            }
         });
 
         return queryParameters;