diff --git a/properties_pane/entity_level/entityLevelConfig.json b/properties_pane/entity_level/entityLevelConfig.json
index e954b6a..bd65fb5 100644
--- a/properties_pane/entity_level/entityLevelConfig.json
+++ b/properties_pane/entity_level/entityLevelConfig.json
@@ -1077,7 +1077,10 @@ making sure that you maintain a proper JSON format.
 						"propertyTooltip": "Expression",
 						"propertyType": "details",
 						"template": "textarea",
-						"markdown": false
+						"markdown": false,
+						"validation": {
+							"required": true
+						}
 					}
 				]
 			}