diff --git a/src/schema/type-defs.ts b/src/schema/type-defs.ts
index ef86b6c..56ef9ed 100644
--- a/src/schema/type-defs.ts
+++ b/src/schema/type-defs.ts
@@ -163,7 +163,7 @@ input InsuranceDataUpdateInput {
     maintananceResponsible: String
     maintananceBenefactor: String
     maintananceAgreement: String
-    hasFixedRate: Boolean!
+    hasFixedRate: Boolean
     fixedRate: Float
     "Projektzuschuss"
     projectAllowance: Float