diff --git a/src/Entity/ExternalEntity.php b/src/Entity/ExternalEntity.php
index edb55fb..edad6e9 100644
--- a/src/Entity/ExternalEntity.php
+++ b/src/Entity/ExternalEntity.php
@@ -159,9 +159,19 @@ class ExternalEntity extends ContentEntityBase implements ExternalEntityInterfac
         $object->{$destination} = substr($this->get($source)->{$property}, strlen($target_bundle) + 1);
       }
       else {
-        $object->{$destination} = $this->get($source)->{$property};
+        $values = $this->get($source)->getValue();
+        if (count($values) > 1) {
+          $object->{$destination} = array();
+          foreach($values as $value_row) {
+            $object->{$destination}[] = $value_row[$property];
+          }
+        }
+        else {
+          $object->{$destination} = $this->get($source)->{$property};
+        }
       }
     }
+
     return $object;
   }
 
@@ -183,7 +193,7 @@ class ExternalEntity extends ContentEntityBase implements ExternalEntityInterfac
         $this->get($destination)->{$property} = $target_bundle . '-' . $object->{$source};
       }
       else {
-        $this->get($destination)->{$property} = $object->{$source};
+        $this->get($destination)->{$property} = isset($object->{$source}) ? $object->{$source} : '';
       }
     }
     return $this;