diff --git a/workflow/engine/classes/class.xmlfield_InputPM.php b/workflow/engine/classes/class.xmlfield_InputPM.php
index a85703f26..c073ad315 100755
--- a/workflow/engine/classes/class.xmlfield_InputPM.php
+++ b/workflow/engine/classes/class.xmlfield_InputPM.php
@@ -386,7 +386,7 @@ function getDynaformsVars ($sProcessUID, $bSystemVars = true, $bIncMulSelFields
         $aFields[] = array ('sName' => 'PIN','sType' => 'system','sLabel' => G::LoadTranslation('ID_TINY_SYSTEM_VARIABLES'));
     }
 
-    $aInvalidTypes = array("title", "subtitle", "file", "button", "reset", "submit", "javascript");
+    $aInvalidTypes = array("title", "subtitle", "file", "button", "reset", "submit", "javascript", "pmconnection");
     $aMultipleSelectionFields = array("listbox", "checkgroup");
 
     if ($bIncMulSelFields != 0) {