diff --git a/sql/migration3.sql b/sql/migration3.sql
new file mode 100644
index 0000000..83db748
--- /dev/null
+++ b/sql/migration3.sql
@@ -0,0 +1,28 @@
+/*
+    It is recommended in the SQLite manual to turn off
+    foreign keys when making schema changes that involve them
+*/
+PRAGMA foreign_keys=OFF;
+BEGIN TRANSACTION;
+-- Change username column (Login) to be case-insensitive
+CREATE TABLE Temp (
+    AccountID    INTEGER NOT NULL,
+    Login        TEXT    NOT NULL UNIQUE COLLATE NOCASE,
+    Password     TEXT    NOT NULL,
+    Selected     INTEGER  DEFAULT 1 NOT NULL,
+    AccountLevel INTEGER NOT NULL,
+    Created      INTEGER DEFAULT (strftime('%s', 'now')) NOT NULL,
+    LastLogin    INTEGER DEFAULT (strftime('%s', 'now')) NOT NULL,
+    BannedUntil  INTEGER DEFAULT 0 NOT NULL,
+    BannedSince  INTEGER DEFAULT 0 NOT NULL,
+    BanReason    TEXT    DEFAULT '' NOT NULL,
+    PRIMARY KEY(AccountID AUTOINCREMENT)
+);
+INSERT INTO Temp SELECT * FROM Accounts;
+DROP TABLE Accounts;
+ALTER TABLE Temp RENAME TO Accounts;
+-- Update DB Version
+UPDATE Meta SET Value = 4 WHERE Key = 'DatabaseVersion';
+UPDATE Meta SET Value = strftime('%s', 'now') WHERE Key = 'LastMigration';
+COMMIT;
+PRAGMA foreign_keys=ON;
diff --git a/sql/tables.sql b/sql/tables.sql
index cbf97f8..564e2ac 100644
--- a/sql/tables.sql
+++ b/sql/tables.sql
@@ -1,6 +1,6 @@
 CREATE TABLE IF NOT EXISTS Accounts (
     AccountID    INTEGER NOT NULL,
-    Login        TEXT    NOT NULL UNIQUE,
+    Login        TEXT    NOT NULL UNIQUE COLLATE NOCASE,
     Password     TEXT    NOT NULL,
     Selected     INTEGER  DEFAULT 1 NOT NULL,
     AccountLevel INTEGER NOT NULL,
diff --git a/src/db/Database.hpp b/src/db/Database.hpp
index 89bc315..240cd76 100644
--- a/src/db/Database.hpp
+++ b/src/db/Database.hpp
@@ -5,7 +5,7 @@
 #include <string>
 #include <vector>
 
-#define DATABASE_VERSION 3
+#define DATABASE_VERSION 4
 
 namespace Database {
 
diff --git a/src/db/init.cpp b/src/db/init.cpp
index 37a6b04..a8d214a 100644
--- a/src/db/init.cpp
+++ b/src/db/init.cpp
@@ -9,6 +9,37 @@
 std::mutex dbCrit;
 sqlite3 *db;
 
+/*
+ * When migrating from DB version 3 to 4, we change the username column
+ * to be case-insensitive. This function ensures there aren't any
+ * duplicates, e.g. username and USERNAME, before doing the migration.
+ * I handled this in the code itself rather than the migration file just so
+ * we can have a more detailed error message than what SQLite provides.
+ */
+static void checkCaseSensitiveDupes() {
+    const char* sql = "SELECT Login, COUNT(*) FROM Accounts GROUP BY LOWER(Login) HAVING COUNT(*) > 1;";
+
+    sqlite3_stmt* stmt;
+    sqlite3_prepare_v2(db, sql, -1, &stmt, NULL);
+    int stat = sqlite3_step(stmt);
+
+    if (stat == SQLITE_DONE) {
+        // no rows returned, so we're good
+        sqlite3_finalize(stmt);
+        return;
+    } else if (stat != SQLITE_ROW) {
+        std::cout << "[FATAL] Failed to check for duplicate accounts: " << sqlite3_errmsg(db) << std::endl;
+        sqlite3_finalize(stmt);
+        exit(1);
+    }
+
+    std::cout << "[FATAL] Case-sensitive duplicates detected in the Login column." << std::endl;
+    std::cout << "Either manually delete/rename the offending accounts, or run the pruning script:" << std::endl;
+    std::cout << "https://github.com/OpenFusionProject/scripts/tree/main/db_migration/caseinsens.py" << std::endl;
+    sqlite3_finalize(stmt);
+    exit(1);
+}
+
 static void createMetaTable() {
     std::lock_guard<std::mutex> lock(dbCrit); // XXX
 
@@ -143,6 +174,10 @@ static void checkMetaTable() {
     }
 
     while (dbVersion != DATABASE_VERSION) {
+        // need to run this before we do any migration logic
+        if (dbVersion == 3)
+            checkCaseSensitiveDupes();
+
         // db migrations
         std::cout << "[INFO] Migrating Database to Version " << dbVersion + 1 << std::endl;