diff --git a/src/components/auth/Invite.js b/src/components/auth/Invite.js
index a420f98a2..c6dca3a65 100644
--- a/src/components/auth/Invite.js
+++ b/src/components/auth/Invite.js
@@ -45,16 +45,16 @@ export default class Invite extends Component {
   form = new Form({
     fields: {
       invite: [...Array(3).fill({
-        name: {
-          label: this.context.intl.formatMessage(messages.nameLabel),
-          // value: '',
-          placeholder: this.context.intl.formatMessage(messages.nameLabel),
-        },
-        email: {
-          label: this.context.intl.formatMessage(messages.emailLabel),
-          // value: '',
-          validators: [email],
-          placeholder: this.context.intl.formatMessage(messages.emailLabel),
+        fields: {
+          name: {
+            label: this.context.intl.formatMessage(messages.nameLabel),
+            placeholder: this.context.intl.formatMessage(messages.nameLabel),
+          },
+          email: {
+            label: this.context.intl.formatMessage(messages.emailLabel),
+            placeholder: this.context.intl.formatMessage(messages.emailLabel),
+            validators: [email],
+          },
         },
       })],
     },
@@ -74,6 +74,10 @@ export default class Invite extends Component {
     const { form } = this;
     const { intl } = this.context;
 
+    const atLeastOneEmailAddress = form.$('invite')
+      .map(invite => invite.$('email').value)
+      .some(emailValue => emailValue.trim() !== '');
+
     return (
       <div className="auth__container auth__container--signup">
         <form className="franz-form auth__form" onSubmit={e => this.submit(e)}>
@@ -96,6 +100,7 @@ export default class Invite extends Component {
           <Button
             type="submit"
             className="auth__button"
+            disabled={!atLeastOneEmailAddress}
             label={intl.formatMessage(messages.submitButtonLabel)}
           />
           <Link
diff --git a/src/helpers/validation-helpers.js b/src/helpers/validation-helpers.js
index eeb12cab7..a8a242d54 100644
--- a/src/helpers/validation-helpers.js
+++ b/src/helpers/validation-helpers.js
@@ -13,7 +13,7 @@ export function email({ field }) {
     isValid = true;
   }
 
-  return [isValid, `${field.label} is not a valid email address`];
+  return [isValid, `${field.label} not valid`];
 }
 
 export function url({ field }) {
diff --git a/src/lib/Form.js b/src/lib/Form.js
index a22699b45..9b8321948 100644
--- a/src/lib/Form.js
+++ b/src/lib/Form.js
@@ -21,8 +21,9 @@ export default class DefaultForm extends Form {
 
   options() {
     return {
-      validateOnInit: false,
-      // validateOnBlur: true,
+      validateOnInit: false, // default: true
+      // validateOnBlur: true, // default: true
+      // validateOnChange: true // default: false
       // // validationDebounceWait: {
       // //   trailing: true,
       // // },