diff --git a/src/ImageOptimize.php b/src/ImageOptimize.php
index 86193867..283fdbda 100644
--- a/src/ImageOptimize.php
+++ b/src/ImageOptimize.php
@@ -351,6 +351,8 @@ static function (ImageTransformerOperationEvent $event): void {
                     $event
                 );
                 if ($tempPath) {
+                    // Remove the old Craft generated transform that's still sitting in the temp directory.
+                    @unlink($event->tempPath);
                     $event->tempPath = $tempPath;
                 }
             }