diff --git a/src/schema.hpp b/src/schema.hpp
index a45149a..89a100c 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -73,6 +73,7 @@
     virtual bool leafEnumHasValue(const schemaPath_& location, const ModuleNodePair& node, const std::string& value) const = 0;
     virtual bool leafIdentityIsValid(const schemaPath_& location, const ModuleNodePair& node, const ModuleValuePair& value) const = 0;
     virtual bool listHasKey(const schemaPath_& location, const ModuleNodePair& node, const std::string& key) const = 0;
+    virtual bool leafIsKey(const std::string& leafPath) const = 0;
     virtual const std::set<std::string> listKeys(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual yang::LeafDataTypes leafType(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual yang::LeafDataTypes leafType(const std::string& path) const = 0;