diff --git a/src/Jobs/RunBuildTaskJob.php b/src/Jobs/RunBuildTaskJob.php
index 435fc8ed..6502efab 100644
--- a/src/Jobs/RunBuildTaskJob.php
+++ b/src/Jobs/RunBuildTaskJob.php
@@ -65,7 +65,7 @@ public function getTitle()
 
     public function process()
     {
-        if (!is_subclass_of($this->TaskClass, BuildTask::class)) {
+        if (!is_a(trim($this->TaskClass), BuildTask::class, true)) {
             throw new \LogicException($this->TaskClass . ' is not a build task');
         }