diff --git a/src/lib/route.js b/src/lib/route.js
new file mode 100644
index 000000000..4eee7620d
--- /dev/null
+++ b/src/lib/route.js
@@ -0,0 +1,15 @@
+module.exports = {};
+
+// try to extract classroom token from either of two routes
+module.exports.getURIClassroomToken = uriPathname => {
+    // first try to match /classes/CLASSROOM_ID/register/CLASSROOM_TOKEN
+    const classRegisterRegexp = /^\/?classes\/\d*\/register\/([a-zA-Z0-9]*)\/?$/;
+    const classRegisterMatch = classRegisterRegexp.exec(uriPathname);
+    if (classRegisterMatch) return classRegisterMatch[1];
+    // if regex match failed, try to match /join/CLASSROOM_TOKEN
+    const joinTokenRegexp = /^\/?join\/([a-zA-Z0-9]*)\/?$/;
+    const joinTokenMatch = joinTokenRegexp.exec(uriPathname);
+    if (joinTokenMatch) return joinTokenMatch[1];
+    // if neither matched
+    return null;
+};
diff --git a/src/views/studentregistration/studentregistration.jsx b/src/views/studentregistration/studentregistration.jsx
index 78443686b..35bfee2ed 100644
--- a/src/views/studentregistration/studentregistration.jsx
+++ b/src/views/studentregistration/studentregistration.jsx
@@ -6,6 +6,7 @@ const React = require('react');
 const api = require('../../lib/api');
 const injectIntl = require('../../lib/intl.jsx').injectIntl;
 const intlShape = require('../../lib/intl.jsx').intlShape;
+const route = require('../../lib/route');
 
 const Deck = require('../../components/deck/deck.jsx');
 const Progression = require('../../components/progression/progression.jsx');
@@ -33,21 +34,8 @@ class StudentRegistration extends React.Component {
     componentDidMount () {
         this.setState({waiting: true}); // eslint-disable-line react/no-did-mount-set-state
 
-        // set uri and params
-        let uri;
-        let params;
-        if (this.props.classroomId === null || typeof this.props.classroomId === 'undefined') {
-            // configure for token-only endpoint
-            uri = `/classtoken/${this.props.classroomToken}`;
-        } else {
-            // configure for endpoint expecting classroomId and token
-            uri = `/classrooms/${this.props.classroomId}`;
-            params = {token: this.props.classroomToken};
-        }
-
         api({
-            uri: uri,
-            params: params
+            uri: `/classtoken/${this.props.classroomToken}`
         }, (err, body, res) => {
             this.setState({waiting: false});
             if (err) {
@@ -57,7 +45,7 @@ class StudentRegistration extends React.Component {
                     })
                 });
             }
-            if (res.statusCode === 404) {
+            if (res.statusCode >= 400) {
                 // TODO: Use react-router for this
                 window.location = '/404';
             }
@@ -178,20 +166,6 @@ const IntlStudentRegistration = injectIntl(StudentRegistration);
 // parse either format of student registration url:
 // "class register": http://scratch.mit.edu/classes/3/register/c0256654e1be
 // "join token": http://scratch.mit.edu/join/c025r54ebe
-let classroomId = null;
-let classroomToken = null;
-const classRegisterRegexp = /^\/?classes\/(\d*)\/register\/([a-zA-Z0-9]*)\/?$/;
-const classRegisterMatch = classRegisterRegexp.exec(document.location.pathname);
-if (classRegisterMatch) {
-    classroomId = classRegisterMatch[1];
-    classroomToken = classRegisterMatch[2];
-} else {
-    const joinTokenRegexp = /^\/?join\/([a-zA-Z0-9]*)\/?$/;
-    const joinTokenMatch = joinTokenRegexp.exec(document.location.pathname);
-    if (joinTokenMatch) {
-        classroomToken = joinTokenMatch[1];
-    }
-}
-const props = {classroomId, classroomToken};
+const props = {classroomToken: route.getURIClassroomToken(document.location.pathname)};
 
 render(<IntlStudentRegistration {...props} />, document.getElementById('app'));
diff --git a/test/unit/lib/route.test.js b/test/unit/lib/route.test.js
new file mode 100644
index 000000000..2acb17599
--- /dev/null
+++ b/test/unit/lib/route.test.js
@@ -0,0 +1,26 @@
+const route = require('../../../src/lib/route');
+
+describe('unit test lib/route.js', () => {
+
+    test('getURIClassroomToken exists', () => {
+        expect(typeof route.getURIClassroomToken).toBe('function');
+    });
+
+    test('getURIClassroomToken parses URI paths like /classes/21/register/r9n5f5xk', () => {
+        let response;
+        response = route.getURIClassroomToken('/classes/21/register/r9n5f5xk');
+        expect(response).toEqual('r9n5f5xk');
+    });
+
+    test('getURIClassroomToken parses URI paths like /join/e2dcfkx95', () => {
+        let response;
+        response = route.getURIClassroomToken('/join/e2dcfkx95');
+        expect(response).toEqual('e2dcfkx95');
+    });
+
+    test('getURIClassroomToken works with trailing slash', () => {
+        let response;
+        response = route.getURIClassroomToken('/join/r9n5f5xk/');
+        expect(response).toEqual('r9n5f5xk');
+    });
+});