diff --git a/circle.yml b/circle.yml
index 1b62faa4e..77e61f102 100644
--- a/circle.yml
+++ b/circle.yml
@@ -10,13 +10,15 @@ machine:
 
 dependencies:
   override:
-    # Upgrade the database version to 3.4.
-    - sudo apt-get purge mongodb-org*
-    - sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
-    - echo "deb [ arch=amd64 ] http://repo.mongodb.org/apt/ubuntu precise/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
-    - sudo apt-get update
-    - sudo apt-get install -y mongodb-org
-    - sudo service mongod restart
+    # TODO: use the following to add in support for MongoDB 3.4.
+    # # Upgrade the database version to 3.4.
+    # - sudo apt-get purge mongodb-org*
+    # - sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6
+    # - echo "deb [ arch=amd64 ] http://repo.mongodb.org/apt/ubuntu precise/mongodb-org/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.4.list
+    # - sudo apt-get update
+    # - sudo apt-get install -y mongodb-org
+    # - sudo service mongod restart
+
     # Install node dependencies.
     - yarn
   cache_directories:
diff --git a/models/user.js b/models/user.js
index b142be5a0..43a34a565 100644
--- a/models/user.js
+++ b/models/user.js
@@ -66,6 +66,15 @@ const UserSchema = new mongoose.Schema({
     required: true
   },
 
+  // TODO: find a way that we can instead utilize MongoDB 3.4's collation
+  // options to build the index in a case insenstive manner:
+  // https://docs.mongodb.com/manual/reference/collation/
+  lowercaseUsername: {
+    type: String,
+    required: true,
+    unique: true
+  },
+
   // This is true when the user account is disabled, no action should be
   // acknowledged when they are disabled. Logins are also prevented.
   disabled: Boolean,
@@ -126,16 +135,6 @@ UserSchema.index({
   background: false
 });
 
-UserSchema.index({
-  'username': 1
-}, {
-  unique: true,
-  collation: {
-    locale: 'en_US',
-    strength: 2
-  }
-});
-
 /**
  * Returns true if the user has all the roles specified.
  */
diff --git a/services/users.js b/services/users.js
index 97cf3e125..1b8045c84 100644
--- a/services/users.js
+++ b/services/users.js
@@ -99,6 +99,10 @@ module.exports = class UsersService {
       .then(() => dstUser.save());
   }
 
+  static castDisplayName(displayName) {
+    return displayName.replace(/ /g, '_').replace(/[^a-zA-Z_]/g, '');
+  }
+
   /**
    * Finds a user given a social profile and if the user does not exist, creates
    * them.
@@ -120,12 +124,14 @@ module.exports = class UsersService {
           return user;
         }
 
+        // TODO: remove displayName reference when we have steps in the FE to handle
+        // the username create flow.
+        let username = UsersService.castDisplayName(displayName);
+
         // The user was not found, lets create them!
         user = new UserModel({
-
-          // TODO: remove displayName reference when we have steps in the FE to handle
-          // the username create flow.
-          username: displayName.replace(/ /g, '_').replace(/[^a-zA-Z_]/g, ''),
+          username,
+          lowercaseUsername: username.toLowerCase(),
           roles: [],
           profiles: [{id, provider}]
         });
@@ -238,6 +244,7 @@ module.exports = class UsersService {
 
             let user = new UserModel({
               username,
+              lowercaseUsername: username.toLowerCase(),
               password: hashedPassword,
               roles: [],
               profiles: [
@@ -677,6 +684,7 @@ module.exports = class UsersService {
     }, {
       $set: {
         username: username,
+        lowercaseUsername: username.toLowerCase(),
         canEditName: false,
         status: 'PENDING'
       }