diff --git a/src/Lib/SqliteImageDb.php b/src/Lib/SqliteImageDb.php
index e25a0a8..23958f3 100644
--- a/src/Lib/SqliteImageDb.php
+++ b/src/Lib/SqliteImageDb.php
@@ -24,6 +24,9 @@ class SqliteImageDb implements ImageDb {
             quality INTEGER NULLABLE,
             content TEXT NOT NULL
         )');
+
+        // Create a unique index on the path and params
+        $this->db->exec('CREATE UNIQUE INDEX IF NOT EXISTS images_path_width_height_quality ON images (path, width, height, quality)');
     }
 
     public function findImage(string $path, ResizeParams $params): Image | null {