diff --git a/src/Database/Expression/CaseExpression.php b/src/Database/Expression/CaseExpression.php
index e987e9cd853..c57a69ee70e 100644
--- a/src/Database/Expression/CaseExpression.php
+++ b/src/Database/Expression/CaseExpression.php
@@ -125,6 +125,8 @@ protected function _addExpressions($conditions, $values, $types) {
 				$value = $k;
 				array_push($this->_values, $value);
 				continue;
+			} elseif ($value instanceof ExpressionInterface) {
+				array_push($this->_values, $value);
 			}
 
 			$type = isset($types[$k]) ? $types[$k] : null;