diff --git a/libs/pbd/pbd/stateful.h b/libs/pbd/pbd/stateful.h
index 550db5a24e..a3cc651eab 100644
--- a/libs/pbd/pbd/stateful.h
+++ b/libs/pbd/pbd/stateful.h
@@ -41,12 +41,12 @@ class Stateful {
 
 	virtual void add_instant_xml (XMLNode&, const std::string& dir);
 	XMLNode *instant_xml (const std::string& str, const std::string& dir);
-        const PBD::ID& id() const { return _id; }
+	const PBD::ID& id() const { return _id; }
 
   protected:
 	XMLNode *_extra_xml;
 	XMLNode *_instant_xml;
-        PBD::ID _id;
+	PBD::ID _id;
 };
 
 #endif /* __pbd_stateful_h__ */