diff --git a/DB/MD5.h b/DB/MD5.h
index b3684866..ec860ae5 100644
--- a/DB/MD5.h
+++ b/DB/MD5.h
@@ -1,64 +1,71 @@
 /*
   Copyright (C) 2018 Johannes Zarl-Zierl <johannes@zarl-zierl.at>
   Copyright (C) 2007-2010 Tuomas Suutari <thsuut@utu.fi>
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
 
   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program (see the file COPYING); if not, write to the
   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
   MA 02110-1301 USA.
 */
 
 #ifndef DB_MD5_H
 #define DB_MD5_H
 
 #include <qglobal.h>
 #include <QString>
 
 namespace DB
 {
 class FileName;
 
 class MD5
 {
 public:
     MD5();
 
     explicit MD5(const QString& md5str);
 
     bool isNull() const;
 
     MD5& operator=(const QString& md5str);
 
     /** Get hex string representation of this.
      * If this->isNull(), returns null string.
      */
     QString toHexString() const;
 
     bool operator==(const MD5 &other) const;
 
     bool operator!=(const MD5& other) const;
 
     bool operator<(const MD5& other) const;
 
+    inline uint hash() const { return (uint) m_v0 ^ m_v1; }
+
 private:
     bool m_isNull;
     qulonglong m_v0;
     qulonglong m_v1;
 };
 
+inline uint qHash(const MD5 &key)
+{
+    return key.hash();
+}
+
 DB::MD5 MD5Sum( const DB::FileName& fileName );
 
 }
 
 #endif /* DB_MD5_H */
 // vi:expandtab:tabstop=4 shiftwidth=4:
diff --git a/DB/MD5Map.cpp b/DB/MD5Map.cpp
index 27bd9902..a055c15c 100644
--- a/DB/MD5Map.cpp
+++ b/DB/MD5Map.cpp
@@ -1,66 +1,66 @@
 /* Copyright (C) 2003-2010 Jesper K. Pedersen <blackie@kde.org>
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program; see the file COPYING.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #include "MD5Map.h"
 
 using namespace DB;
 
 void MD5Map::insert( const MD5& md5sum, const DB::FileName& fileName )
 {
     m_map.insert( md5sum, fileName );
     m_i_map.insert( fileName, md5sum );
 }
 
 DB::FileName MD5Map::lookup( const MD5& md5sum ) const
 {
     return m_map[md5sum];
 }
 
 MD5 MD5Map::lookupFile( const DB::FileName& fileName ) const
 {
     return m_i_map[fileName];
 }
 
 bool MD5Map::contains( const MD5& md5sum ) const
 {
     return m_map.contains( md5sum );
 }
 
 bool MD5Map::containsFile( const DB::FileName& fileName ) const
 {
     return m_i_map.contains( fileName );
 }
 
 void MD5Map::clear()
 {
     m_map.clear();
     m_i_map.clear();
 }
 
 DB::FileNameSet DB::MD5Map::diff( const MD5Map& other ) const
 {
     DB::FileNameSet res;
 
-    for( QMap<MD5, DB::FileName>::ConstIterator it = m_map.begin(); it != m_map.end(); ++it ) {
+    for( MD5FileMap::ConstIterator it = m_map.begin(); it != m_map.end(); ++it ) {
         if ( other.lookup( it.key() ) != it.value() )
             res.insert( it.value() );
     }
 
     return res;
 }
 // vi:expandtab:tabstop=4 shiftwidth=4:
diff --git a/DB/MD5Map.h b/DB/MD5Map.h
index 28a3d078..fdb8d344 100644
--- a/DB/MD5Map.h
+++ b/DB/MD5Map.h
@@ -1,54 +1,57 @@
 /* Copyright (C) 2003-2010 Jesper K. Pedersen <blackie@kde.org>
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program; see the file COPYING.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #ifndef MD5MAP_H
 #define MD5MAP_H
 #include <qstring.h>
-#include <qmap.h>
+#include <qhash.h>
 #include "MD5.h"
 #include <DB/FileName.h>
 
 namespace DB
 {
+    typedef QHash<MD5, DB::FileName> MD5FileMap;
+    typedef QHash<DB::FileName, MD5> FileMD5Map;
+
 /**
    This class may be overridden by a which wants to store md5 information
    directly in a database, rather than in a map in memory.
 **/
 class MD5Map
 {
 public:
     virtual ~MD5Map() {}
     virtual void insert( const MD5& md5sum, const DB::FileName& fileName );
     virtual DB::FileName lookup( const MD5& md5sum ) const;
     virtual MD5 lookupFile( const DB::FileName& fileName ) const;
     virtual bool contains( const MD5& md5sum ) const;
     virtual bool containsFile( const DB::FileName& fileName ) const;
     virtual void clear();
     virtual DB::FileNameSet diff( const MD5Map& other ) const;
 
 private:
-    QMap<MD5, DB::FileName> m_map;
-    QMap<DB::FileName, MD5> m_i_map;
+    MD5FileMap m_map;
+    FileMD5Map m_i_map;
 };
 
 }
 
 
 #endif /* MD5MAP_H */
 
 // vi:expandtab:tabstop=4 shiftwidth=4: