diff --git a/setup/runtimeenv.class.inc.php b/setup/runtimeenv.class.inc.php
index b6018ec65..fedc6a15a 100644
--- a/setup/runtimeenv.class.inc.php
+++ b/setup/runtimeenv.class.inc.php
@@ -1070,7 +1070,7 @@ class RunTimeEnvironment
 	{
 		if ($this->sFinalEnv != $this->sTargetEnv)
 		{
-			SetupUtils::tidydir($this->sTargetEnv);
+			SetupUtils::tidydir(APPROOT.$this->sTargetEnv);
 		}
 	}