diff --git a/hoot-core/src/main/cpp/hoot/core/criterion/ChainCriterion.h b/hoot-core/src/main/cpp/hoot/core/criterion/ChainCriterion.h
index 2f12520..e2dd204 100644
--- a/hoot-core/src/main/cpp/hoot/core/criterion/ChainCriterion.h
+++ b/hoot-core/src/main/cpp/hoot/core/criterion/ChainCriterion.h
@@ -57,6 +57,8 @@ public:
virtual QString getDescription() const
{ return "Allows for chaining criteria together (logical AND)"; }
+ QString toString() const;
+
protected:
ChainCriterion(const std::vector<std::shared_ptr<ElementCriterion>>& criteria);