diff --git a/src/main/java/net/frozenorb/apiv3/APIv3.java b/src/main/java/net/frozenorb/apiv3/APIv3.java
index 8338fdf..bfe0cfd 100644
--- a/src/main/java/net/frozenorb/apiv3/APIv3.java
+++ b/src/main/java/net/frozenorb/apiv3/APIv3.java
@@ -238,6 +238,7 @@ public final class APIv3 extends AbstractVerticle {
 		});
 		database.getCollection("users").createIndexes(ImmutableList.of(
 				new IndexModel(new Document("lastUsername", 1)),
+				new IndexModel(new Document("lastUsernameLower", 1)),
 				new IndexModel(new Document("emailToken", 1))
 		), (a, b) -> {
 		});
diff --git a/src/main/java/net/frozenorb/apiv3/model/User.java b/src/main/java/net/frozenorb/apiv3/model/User.java
index d3a7a82..abae471 100644
--- a/src/main/java/net/frozenorb/apiv3/model/User.java
+++ b/src/main/java/net/frozenorb/apiv3/model/User.java
@@ -41,6 +41,7 @@ public final class User {
 
 	@Getter @Id @JsonSerialize(using = UuidJsonSerializer.class) @JsonDeserialize(using = UuidJsonDeserializer.class) private UUID id;
 	@Getter private String lastUsername;
+    @Getter private String lastUsernameLower;
 	@Getter @ExcludeFromReplies private Map<String, Instant> aliases = new HashMap<>();
 	@Getter @ExcludeFromReplies @Setter private String totpSecret;
 	@Getter @ExcludeFromReplies private String password;
@@ -148,6 +149,10 @@ public final class User {
 		usersCollection.find(new Document("lastUsername", lastUsername)).first(SyncUtils.vertxWrap(callback));
 	}
 
+    public static void findByLastUsernameLower(String lastUsernameLower, SingleResultCallback<User> callback) {
+        usersCollection.find(new Document("lastUsernameLower", lastUsernameLower)).first(SyncUtils.vertxWrap(callback));
+    }
+
 	public static void findOrCreateByIdGrouped(Map<UUID, String> search, SingleResultCallback<Map<UUID, User>> callback) {
 		usersCollection.find(new Document("_id", new Document("$in", search.keySet()))).into(new LinkedList<>(), SyncUtils.vertxWrap((users, error) -> {
 			if (error != null) {
@@ -205,6 +210,7 @@ public final class User {
 	public User(UUID id, String lastUsername) {
 		this.id = id;
 		this.lastUsername = lastUsername;
+        this.lastUsernameLower = lastUsername.toLowerCase();
 		this.aliases = new HashMap<>();
 		this.lastSeenAt = Instant.now();
 		this.firstSeenAt = Instant.now();
@@ -215,6 +221,7 @@ public final class User {
 	public void updateUsername(String newUsername) {
 		this.aliases.put(newUsername, Instant.now());
 		this.lastUsername = newUsername;
+        this.lastUsernameLower = newUsername.toLowerCase();
 	}
 
 	public void checkNameCollisions(SingleResultCallback<Void> callback) {
diff --git a/src/main/java/net/frozenorb/apiv3/route/users/GETUsersIdVerifyPassword.java b/src/main/java/net/frozenorb/apiv3/route/users/GETUsersIdVerifyPassword.java
index 31883ed..5669101 100644
--- a/src/main/java/net/frozenorb/apiv3/route/users/GETUsersIdVerifyPassword.java
+++ b/src/main/java/net/frozenorb/apiv3/route/users/GETUsersIdVerifyPassword.java
@@ -22,7 +22,7 @@ public final class GETUsersIdVerifyPassword implements Handler<RoutingContext> {
 		User user = SyncUtils.runBlocking(v -> User.findById(ctx.request().getParam("userId"), v));
 
 		if (user == null) {
-			user = SyncUtils.runBlocking(v -> User.findByLastUsername(ctx.request().getParam("userId"), v));
+			user = SyncUtils.runBlocking(v -> User.findByLastUsernameLower(ctx.request().getParam("userId"), v));
 		}
 
 		if (user == null) {