diff --git a/src/Plugin/migrate/process/ParseEntityLookup.php b/src/Plugin/migrate/process/ParseEntityLookup.php
index b148230..c649e35 100644
--- a/src/Plugin/migrate/process/ParseEntityLookup.php
+++ b/src/Plugin/migrate/process/ParseEntityLookup.php
@@ -139,7 +139,7 @@ public function transform($value, MigrateExecutableInterface $migrate_executable
             return NULL;
         }
 
-        $delimiter = $this->configuration['delimiter'] ?: self::default_delimiter;
+        $delimiter = @$this->configuration['delimiter'] ?: self::default_delimiter;
 
         // split the source value into fields using the defined delimiter
         $source_values = explode($delimiter, $value);
@@ -238,4 +238,4 @@ function applyDefaults($entity_lookup_config, $defaults): array {
     }
 
 
-}
\ No newline at end of file
+}