diff --git a/src/schema.hpp b/src/schema.hpp
index 6970fe9..a85961b 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -63,13 +63,13 @@
 public:
     virtual ~Schema();
 
-    virtual bool isContainer(const schemaPath_& location, const ModuleNodePair& node) const = 0;
-    virtual bool isLeaf(const schemaPath_& location, const ModuleNodePair& node) const = 0;
+    bool isContainer(const schemaPath_& location, const ModuleNodePair& node) const;
+    bool isLeaf(const schemaPath_& location, const ModuleNodePair& node) const;
+    bool isList(const schemaPath_& location, const ModuleNodePair& node) const;
+    bool isPresenceContainer(const schemaPath_& location, const ModuleNodePair& node) const;
     virtual yang::NodeTypes nodeType(const std::string& path) const = 0;
     virtual yang::NodeTypes nodeType(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     virtual bool isModule(const std::string& name) const = 0;
-    virtual bool isList(const schemaPath_& location, const ModuleNodePair& node) const = 0;
-    virtual bool isPresenceContainer(const schemaPath_& location, const ModuleNodePair& node) const = 0;
     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;