diff --git a/src/components/structures/auth/Registration.js b/src/components/structures/auth/Registration.js
index 0d3fe29967..af51ca7df0 100644
--- a/src/components/structures/auth/Registration.js
+++ b/src/components/structures/auth/Registration.js
@@ -98,8 +98,8 @@ module.exports = React.createClass({
             // component without it.
             matrixClient: null,
 
-            // the capabilities object from the server
-            serverCaps: null,
+            // whether the HS requires an ID server to register with a threepid
+            serverRequiresIdServer: null,
 
             // The user ID we've just registered
             registeredUsername: null,
@@ -212,17 +212,16 @@ module.exports = React.createClass({
             idBaseUrl: isUrl,
         });
 
-        let caps = null;
+        let serverRequiresIdServer = true;
         try {
-            caps = await cli.getServerCapabilities();
-            caps = caps || {};
+            serverRequiresIdServer = await cli.doesServerRequireIdServerParam();
         } catch (e) {
-            console.log("Unable to fetch server capabilities", e);
+            console.log("Unable to determine is server needs id_server param", e);
         }
 
         this.setState({
             matrixClient: cli,
-            serverCaps: caps,
+            serverRequiresIdServer,
             busy: false,
         });
         try {
@@ -564,7 +563,7 @@ module.exports = React.createClass({
                 flows={this.state.flows}
                 serverConfig={this.props.serverConfig}
                 canSubmit={!this.state.serverErrorIsFatal}
-                serverCapabilities={this.state.serverCaps}
+                serverRequiresIdServer={this.state.serverRequiresIdServer}
             />;
         }
     },
diff --git a/src/components/views/auth/RegistrationForm.js b/src/components/views/auth/RegistrationForm.js
index 368ab599e3..cf1b074fe1 100644
--- a/src/components/views/auth/RegistrationForm.js
+++ b/src/components/views/auth/RegistrationForm.js
@@ -55,7 +55,7 @@ module.exports = React.createClass({
         flows: PropTypes.arrayOf(PropTypes.object).isRequired,
         serverConfig: PropTypes.instanceOf(ValidatedServerConfig).isRequired,
         canSubmit: PropTypes.bool,
-        serverCapabilities: PropTypes.object,
+        serverRequiresIdServer: PropTypes.bool,
     },
 
     getDefaultProps: function() {
@@ -437,9 +437,8 @@ module.exports = React.createClass({
     },
 
     _showEmail() {
-        const idServerRequired = !this.props.serverCapabilities['me.dbkr.idomyownemail'];
         const haveIs = Boolean(this.props.serverConfig.isUrl);
-        if ((idServerRequired && !haveIs) || !this._authStepIsUsed('m.login.email.identity')) {
+        if ((this.props.serverRequiresIdServer && !haveIs) || !this._authStepIsUsed('m.login.email.identity')) {
             return false;
         }
         return true;