diff --git a/libretroshare/src/ft/ftchunkmap.cc b/libretroshare/src/ft/ftchunkmap.cc
index d3dcfa849..2af63480f 100644
--- a/libretroshare/src/ft/ftchunkmap.cc
+++ b/libretroshare/src/ft/ftchunkmap.cc
@@ -221,7 +221,7 @@ uint32_t ChunkMap::getAvailableChunk(uint32_t start_location,const std::string&
 	const std::vector<uint32_t> peer_chunks(it->second) ;
 #endif
 
-	for(uint i=0;i<_map.size();++i)
+	for(unsigned int i=0;i<_map.size();++i)
 	{
 		uint32_t j = (start_location+i)%_map.size() ;
 
diff --git a/libretroshare/src/ft/ftchunkmap.h b/libretroshare/src/ft/ftchunkmap.h
index 0732253cd..f2f06115d 100644
--- a/libretroshare/src/ft/ftchunkmap.h
+++ b/libretroshare/src/ft/ftchunkmap.h
@@ -80,6 +80,7 @@ class ChunkMap
 		// Constructor. Decides what will be the size of chunks and how many there will be.
 
 		ChunkMap(uint64_t file_size) ;
+		virtual ~ChunkMap() {}
 
       // Returns an slice of data to be asked to the peer within a chunk.
 		// If a chunk is already been downloaded by this peer, take a slice at