diff --git a/src/features/global/cards/utils/addCardForm.ts b/src/features/global/cards/utils/addCardForm.ts
index 1dd6adb..a4092a2 100644
--- a/src/features/global/cards/utils/addCardForm.ts
+++ b/src/features/global/cards/utils/addCardForm.ts
@@ -8,12 +8,12 @@ export const AddCardForm = () => {
             task: '',
             description: '',
             partId: 0,
-            workingDays: null,
+            workingDays: '',
             dods: '',
             assignees: [],
         },
         validate: {
-            workingDays: (value) => (value === null || value <= 0 ? 'You must work at least 0.5 days' : null),
+            workingDays: (value) => (value === null || value === '' || parseFloat(value) <= 0 ? 'You must work at least 0.5 days' : null),
         }
     });
 };
\ No newline at end of file
diff --git a/src/store/api/types/queryParams.ts b/src/store/api/types/queryParams.ts
index faa3dd3..ee544f3 100644
--- a/src/store/api/types/queryParams.ts
+++ b/src/store/api/types/queryParams.ts
@@ -37,7 +37,7 @@ export interface CreateCard {
         asWho: string,
         task: string,
         description: string,
-        workingDays: number | null,
+        workingDays: number | string,
         dods: string,
         partId: number,
         assignees: string[];