diff --git a/src/yang_schema.hpp b/src/yang_schema.hpp
index e610383..1165094 100644
--- a/src/yang_schema.hpp
+++ b/src/yang_schema.hpp
@@ -36,6 +36,7 @@
     bool leafEnumHasValue(const schemaPath_& location, const ModuleNodePair& node, const std::string& value) const override;
     bool leafIdentityIsValid(const schemaPath_& location, const ModuleNodePair& node, const ModuleValuePair& value) const override;
     bool listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const override;
+    bool leafIsKey(const std::string& leafPath) const override;
     const std::set<std::string> listKeys(const schemaPath_& location, const ModuleNodePair& node) const override;
     yang::LeafDataTypes leafType(const schemaPath_& location, const ModuleNodePair& node) const override;
     yang::LeafDataTypes leafType(const std::string& path) const override;