diff --git a/src/app/component/angularjs-dropdown-multiselect.controller.js b/src/app/component/angularjs-dropdown-multiselect.controller.js
index e837cc99..6e84467c 100644
--- a/src/app/component/angularjs-dropdown-multiselect.controller.js
+++ b/src/app/component/angularjs-dropdown-multiselect.controller.js
@@ -100,6 +100,13 @@ export default function dropdownMultiselectController(
 		searchFilter: $scope.searchFilter || '',
 	};
 
+	if (!$scope.selectedModel || !Array.isArray($scope.selectedModel)) {
+		throw new TypeError(
+			'selected-model type error. Must be initialized as an empty array.',
+			'angularjs-dropdown-multiselect.controller.js',
+			103);
+	}
+
 	angular.extend(settings, $scope.extraSettings || []);
 	angular.extend(externalEvents, $scope.events || []);
 	angular.extend(texts, $scope.translationTexts);