diff --git a/alib2data/src/tree/RankedTreeBase.h b/alib2data/src/tree/RankedTreeBase.h
index 06ca1615ccd54145a43cce29f8fe17f9a2204e52..a0472bf939465681d51367114a42f5b1a9be0acd 100644
--- a/alib2data/src/tree/RankedTreeBase.h
+++ b/alib2data/src/tree/RankedTreeBase.h
@@ -1,5 +1,5 @@
 /*
- * TreeBase.h
+ * RankedTreeBase.h
  *
  *  Created on: Nov 16, 2014
  *      Author: Stepan Plachy
@@ -20,7 +20,7 @@ namespace tree {
 class RankedTreeBase : public tree::TreeBase {
 public:
 	virtual RankedTreeBase * clone ( ) const = 0;
-	virtual RankedTreeBase * plunder ( ) &&	 = 0;
+	virtual RankedTreeBase * plunder ( ) && = 0;
 
 	virtual const std::set < alphabet::RankedSymbol > & getAlphabet ( ) const = 0;
 	virtual void extendAlphabet ( const std::set < alphabet::RankedSymbol > & symbols ) = 0;
diff --git a/alib2data/src/tree/UnrankedTreeBase.h b/alib2data/src/tree/UnrankedTreeBase.h
index b3a2cbd403547245d8898690a36853443e2aeab0..813a718a02c7bdb45aa020c95233d7a744083dd1 100644
--- a/alib2data/src/tree/UnrankedTreeBase.h
+++ b/alib2data/src/tree/UnrankedTreeBase.h
@@ -1,5 +1,5 @@
 /*
- * TreeBase.h
+ * UnrankedTreeBase.h
  *
  *  Created on: Nov 16, 2014
  *      Author: Jan Tranicek
@@ -20,7 +20,7 @@ namespace tree {
 class UnrankedTreeBase : public TreeBase {
 public:
 	virtual UnrankedTreeBase * clone ( ) const = 0;
-	virtual UnrankedTreeBase * plunder ( ) &&  = 0;
+	virtual UnrankedTreeBase * plunder ( ) && = 0;
 
 	virtual const std::set < alphabet::Symbol > & getAlphabet ( ) const = 0;
 	virtual void extendAlphabet ( const std::set < alphabet::Symbol > & symbols ) = 0;