diff --git a/modules/backend/widgets/Lists.php b/modules/backend/widgets/Lists.php
index 3c92acc3c..cddbb5949 100644
--- a/modules/backend/widgets/Lists.php
+++ b/modules/backend/widgets/Lists.php
@@ -920,6 +920,16 @@ class Lists extends WidgetBase
         return $this->evalTextTypeValue($record, $column, $value);
     }
 
+    /**
+     * Common mistake, relation is not a valid list column.
+     * @deprecated Remove if year >= 2018
+     */
+    protected function evalRelationTypeValue($record, $column, $value)
+    {
+        traceLog(sprintf('Warning: List column type "relation" for class "%s" is not valid.', get_class($record)));
+        return $this->evalTextTypeValue($record, $column, $value);
+    }
+
     /**
      * Process as partial reference
      */