diff --git a/src/utils/workflows.spec.ts b/src/utils/workflows.spec.ts
index 1721d5e..0e29a9e 100644
--- a/src/utils/workflows.spec.ts
+++ b/src/utils/workflows.spec.ts
@@ -23,6 +23,10 @@ describe('workflows utils', () => {
   });
 
   describe('parseGracePeriodInput', () => {
+    it('accepts numeric values from number-backed inputs', () => {
+      expect(parseGracePeriodInput(7)).toEqual({ value: 7 });
+      expect(parseGracePeriodInput(0)).toEqual({ value: 0 });
+    });
     it('returns fallback for empty input', () => {
       expect(parseGracePeriodInput('')).toEqual({
         value: DEFAULT_GRACE_PERIOD_DAYS,
diff --git a/src/utils/workflows.ts b/src/utils/workflows.ts
index 4abc896..bb23c0d 100644
--- a/src/utils/workflows.ts
+++ b/src/utils/workflows.ts
@@ -10,10 +10,10 @@ export function toGracePeriodInputValue(
 }
 
 export function parseGracePeriodInput(
-  input: string,
+  input: string | number | null | undefined,
   fallback = DEFAULT_GRACE_PERIOD_DAYS,
 ): { value: number; error?: string } {
-  const trimmed = input.trim();
+  const trimmed = String(input ?? '').trim();
   if (trimmed === '') {
     return { value: fallback };
   }
diff --git a/src/views/workflows/partials/StepDefinitionForm.vue b/src/views/workflows/partials/StepDefinitionForm.vue
index 0c56fc9..430c88f 100644
--- a/src/views/workflows/partials/StepDefinitionForm.vue
+++ b/src/views/workflows/partials/StepDefinitionForm.vue
@@ -343,18 +343,18 @@ function initForm() {
 function validate(): boolean {
   Object.keys(errors).forEach((key) => delete errors[key]);
   errorMessage.value = '';
-
+  const normalizedGracePeriodInput = String(gracePeriodDaysInput.value ?? '');
   if (!form.name?.trim()) {
     errors.name = 'Step name is required';
     return false;
   }
 
-  if (gracePeriodDaysInput.value.trim() === '') {
+  if (normalizedGracePeriodInput.trim() === '') {
     // Empty input is treated as "use current upstream default" rather than
     // persisting a nullable value for steps.
     form.gracePeriodDays = effectiveDefaultGracePeriodDays;
   } else {
-    const parsedGracePeriod = parseGracePeriodInput(gracePeriodDaysInput.value);
+    const parsedGracePeriod = parseGracePeriodInput(normalizedGracePeriodInput);
     if (parsedGracePeriod.error) {
       errors.gracePeriodDays = parsedGracePeriod.error;
       return false;