diff --git a/src/internals/api.ts b/src/internals/api.ts
index f2ca48b1..2fac899c 100644
--- a/src/internals/api.ts
+++ b/src/internals/api.ts
@@ -286,12 +286,14 @@ export class Clockodo {
         } | {
             customersId: number;
             servicesId: number;
+            billable: Billable;
             timeSince: string;
             lumpSum: number;
         } | {
             customersId: number;
             lumpSumsId: number;
             lumpSumsAmount: number;
+            billable: Billable;
             timeSince: string;
         },
         options?: object
diff --git a/src/internals/utilities/requiredParams.ts b/src/internals/utilities/requiredParams.ts
index 5a6a4811..4cc45ca0 100644
--- a/src/internals/utilities/requiredParams.ts
+++ b/src/internals/utilities/requiredParams.ts
@@ -1,8 +1,8 @@
 export const ADD_ABSENCE = ["dateSince", "dateUntil", "type"];
 export const ADD_CUSTOMER = ["name"];
 export const ADD_TIME_ENTRY = ["customersId", "servicesId", "billable", "timeSince", "timeUntil"];
-export const ADD_LUMP_SUM_ENTRY = ["customersId", "servicesId", "timeSince", "lumpSum"];
-export const ADD_RECURRING_LUMP_SUM_ENTRY = ["customersId", "lumpSumsAmount", "lumpSumsId", "timeSince"];
+export const ADD_LUMP_SUM_ENTRY = ["customersId", "servicesId", "billable", "timeSince", "lumpSum"];
+export const ADD_RECURRING_LUMP_SUM_ENTRY = ["customersId", "lumpSumsAmount", "lumpSumsId", "billable", "timeSince"];
 export const ADD_PROJECT = ["name", "customersId"];
 export const ADD_SERVICE = ["name"];
 export const ADD_USER = ["name", "number", "email", "role"];
diff --git a/tests/integration/integration.test.ts b/tests/integration/integration.test.ts
index 82281396..45e54a5b 100644
--- a/tests/integration/integration.test.ts
+++ b/tests/integration/integration.test.ts
@@ -184,9 +184,9 @@ const hasCredentials = typeof process.env.CLOCKODO_USER === "string" && typeof p
                     customersId: lumpSum.customersId,
                     lumpSumsId: lumpSum.lumpSumsId,
                     lumpSumsAmount: lumpSum.lumpSumsAmount,
+                    billable: 2,
                     timeSince: lumpSum.timeSince,
                 }, {
-                    billable: 2,
                     text: lumpSum.text,
                 });