diff --git a/src/models/SignupForm.ts b/src/models/SignupForm.ts
index b2e038b..750f751 100644
--- a/src/models/SignupForm.ts
+++ b/src/models/SignupForm.ts
@@ -6,6 +6,7 @@ import { Question } from "@components/SignupQuestionsWidget";
 export interface SignupForm {
   id?: number;
   title: string;
+  visible: boolean;
   start_time: string;
   end_time: string;
   questions: Question[];
diff --git a/src/pages/admin/EventCreatePage.tsx b/src/pages/admin/EventCreatePage.tsx
index 5be772d..e8f64fa 100644
--- a/src/pages/admin/EventCreatePage.tsx
+++ b/src/pages/admin/EventCreatePage.tsx
@@ -105,7 +105,7 @@ class EventCreatePage extends React.Component<EventCreatePageProps, EventCreateP
 
     try {
       const payload = data.formData;
-      if (payload.image.startsWith("http")) payload.image = undefined;
+      if (typeof payload.image === "string" && payload.image.startsWith("http")) payload.image = undefined;
       payload.signup_id = payload.signupForm;
       payload.tag_id = payload.tags;
       if (payload.id === undefined) {
@@ -211,7 +211,7 @@ class EventCreatePage extends React.Component<EventCreatePageProps, EventCreateP
           type: ["string", "null"],
           format: formData.image ? "uri-reference" : "data-url",
           title: "Override tag icon with image",
-          default: ""
+          default: undefined
         },
         finnish_section_divider: {
           title: "Finnish",
diff --git a/src/pages/admin/SignupCreatePage.tsx b/src/pages/admin/SignupCreatePage.tsx
index a3b807f..3b3e2ac 100644
--- a/src/pages/admin/SignupCreatePage.tsx
+++ b/src/pages/admin/SignupCreatePage.tsx
@@ -133,13 +133,13 @@ class SignupCreatePage extends React.Component<SignupCreatePageProps, SignupCrea
         visible: {
           type: "boolean",
           title: "Visible",
-          default: true,
+          default: false,
         },
         quota: {
-          type: ["integer", "null"],
+          type: ["integer"],
           title: "Quota",
           minimum: 0,
-          default: null,
+          default: 0,
         },
         start_time: {
           type: "string",
diff --git a/src/views/SignUpPage/SignUpPageView.tsx b/src/views/SignUpPage/SignUpPageView.tsx
index 34f4b3f..92ea3e1 100644
--- a/src/views/SignUpPage/SignUpPageView.tsx
+++ b/src/views/SignUpPage/SignUpPageView.tsx
@@ -26,7 +26,7 @@ const renderList = (signUpForm: SignupForm) => {
   return (
     <>
       <h6>
-        Ilmoittautuneet {signUpForm.quota && (`(${signUpForm.signups.length}/${signUpForm.quota})`)}:
+        Ilmoittautuneet{signUpForm.quota > 0 && (` (${signUpForm.signups.length}/${signUpForm.quota})`)}:
       </h6>
       <ol>
         {signUpForm.signups.map((s, idx) => (