diff --git a/hoot-core/src/main/cpp/hoot/core/conflate/matching/OptimalConstrainedMatches.h b/hoot-core/src/main/cpp/hoot/core/conflate/matching/OptimalConstrainedMatches.h
index 82d8d4d..394f50b 100644
--- a/hoot-core/src/main/cpp/hoot/core/conflate/matching/OptimalConstrainedMatches.h
+++ b/hoot-core/src/main/cpp/hoot/core/conflate/matching/OptimalConstrainedMatches.h
@@ -53,7 +53,7 @@ public:
* scores. All matches will be considered so if you don't want matches below a threshold included
* then don't add them.
*/
- virtual std::vector<const Match*> calculateSubset() override;
+ virtual std::vector<ConstMatchPtr> calculateSubset() override;
private: