diff --git a/src/backends/matrix.js b/src/backends/matrix.js
index f175af5526840d14703ffa4937fd668f782f9c8a..ad5e41f3f62147928b55b01a2a9159ac3ca39435 100644
--- a/src/backends/matrix.js
+++ b/src/backends/matrix.js
@@ -25,7 +25,7 @@ class MatrixBackend extends BaseBackend {
   set userId(value) {
     if (value !== undefined) {
       const matrixId = utils.splitMatrixId(value);
-      const homeServerUrl = 'https://' + matrixId.homeServer
+      const homeServerUrl = 'https://' + matrixId.homeServer;
 
       this.api = sdk.createClient(homeServerUrl);
       this.userId = value;
diff --git a/src/utils.js b/src/utils.js
index 9bb5d2f490f5a2cfa8edf18f1b83b269dce6eae4..1606fc26ca0b9dd46d728a528a877023a7ddbbf7 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -17,6 +17,7 @@
  * Split a Matrix ID into local part and homeserver
  *
  * @param {string} matrixId
+ * @return {Object}
  *
  * @example
  *   splitMatrixId('@foo:example.com')
@@ -24,11 +25,11 @@
  */
 export function splitMatrixId(matrixId) {
   if (typeof matrixId !== 'string') {
-    throw 'Passed Matrix ID must be a string';
+    throw new Error('Passed Matrix ID must be a string');
   } else if (matrixId.substr(0, 1) !== '@') {
-    throw 'Passed Matrix ID must begin with @';
+    throw new Error('Passed Matrix ID must begin with @');
   } else if (matrixId.indexOf(':') < 2) {
-    throw 'Passed Matrix ID must contain : to separate local part and home server';
+    throw new Error('Passed Matrix ID must contain :');
   }
 
   const localPart = matrixId.substr(1).substr(0, matrixId.indexOf(':'));
@@ -36,6 +37,6 @@ export function splitMatrixId(matrixId) {
 
   return {
     'localPart': localPart,
-    'homeServer': homeServer
-  }
+    'homeServer': homeServer,
+  };
 }