diff --git a/public/intl/messages/en-US.json b/public/intl/messages/en-US.json
index 97078ba27..552381ef1 100644
--- a/public/intl/messages/en-US.json
+++ b/public/intl/messages/en-US.json
@@ -442,6 +442,7 @@
     "go-to-settings": "Go to settings",
     "incorrect-username-password": "Incorrect username and/or password.",
     "invalid-domain": "Invalid domain. Do not include http/https.",
+    "invalid-value": "Invalid value",
     "min-password-length": "Minimum length of {n} characters",
     "new-version-available": "A new version of Umami {version} is available!",
     "no-data-available": "No data available.",
diff --git a/src/app/(main)/websites/[websiteId]/(reports)/funnels/FunnelEditForm.tsx b/src/app/(main)/websites/[websiteId]/(reports)/funnels/FunnelEditForm.tsx
index 99cc52bf5..d9fa644bf 100644
--- a/src/app/(main)/websites/[websiteId]/(reports)/funnels/FunnelEditForm.tsx
+++ b/src/app/(main)/websites/[websiteId]/(reports)/funnels/FunnelEditForm.tsx
@@ -200,7 +200,14 @@ export function FunnelEditForm({
       <FormField name="name" label={t(labels.name)} rules={{ required: t(labels.required) }}>
         <TextField autoFocus />
       </FormField>
-      <FormField name="window" label={t(labels.window)} rules={{ required: t(labels.required) }}>
+      <FormField
+        name="window"
+        label={t(labels.window)}
+        rules={{
+          required: t(labels.required),
+          pattern: { value: /^[1-9][0-9]*$/, message: t(labels.invalidValue) || 'Must be greater than 0' },
+        }}
+      >
         <TextField />
       </FormField>
       <FormFieldArray
diff --git a/src/components/messages.ts b/src/components/messages.ts
index 14feeafdd..cc0d69d4b 100644
--- a/src/components/messages.ts
+++ b/src/components/messages.ts
@@ -362,6 +362,7 @@ export const labels: Record<string, string> = {
   slug: 'label.slug',
   audience: 'label.audience',
   invalidUrl: 'label.invalid-url',
+  invalidValue: 'message.invalid-value',
   environment: 'label.environment',
   criteria: 'label.criteria',
   share: 'label.share',