diff --git a/src/core/Database.cpp b/src/core/Database.cpp
index 67f39b73a..2fe208909 100644
--- a/src/core/Database.cpp
+++ b/src/core/Database.cpp
@@ -20,7 +20,8 @@
 #include <QtCore/QFile>
 #include <QtCore/QXmlStreamReader>
 
-#include "Metadata.h"
+#include "core/Group.h"
+#include "core/Metadata.h"
 #include "crypto/Random.h"
 #include "format/KeePass2.h"
 
@@ -46,7 +47,10 @@ const Group* Database::rootGroup() const
 
 void Database::setRootGroup(Group* group)
 {
-    Q_ASSERT(group == 0 || group->database() == this);
+    if (group != 0) {
+        group->setParent(this);
+    }
+
     m_rootGroup = group;
 }
 
diff --git a/src/core/Database.h b/src/core/Database.h
index 78c132ee8..8876b8382 100644
--- a/src/core/Database.h
+++ b/src/core/Database.h
@@ -18,13 +18,15 @@
 #ifndef KEEPASSX_DATABASE_H
 #define KEEPASSX_DATABASE_H
 
-#include "Group.h"
-
+#include <QtCore/QDateTime>
 #include <QtCore/QHash>
 #include <QtGui/QIcon>
 
+#include "core/Uuid.h"
 #include "keys/CompositeKey.h"
 
+class Entry;
+class Group;
 class Metadata;
 
 struct DeletedObject
@@ -48,7 +50,12 @@ public:
     Database();
     Group* rootGroup();
     const Group* rootGroup() const;
+
+    /**
+     * Sets group as the root group and takes ownership of it.
+     */
     void setRootGroup(Group* group);
+
     Metadata* metadata();
     const Metadata* metadata() const;
     Entry* resolveEntry(const Uuid& uuid);
@@ -66,6 +73,10 @@ public:
     void setCompressionAlgo(Database::CompressionAlgorithm algo);
     void setTransformRounds(quint64 rounds);
     void setKey(const CompositeKey& key, const QByteArray& transformSeed);
+
+    /**
+     * Sets the database key and generates a random transform seed.
+     */
     void setKey(const CompositeKey& key);
 
 Q_SIGNALS:
diff --git a/src/core/Entry.cpp b/src/core/Entry.cpp
index 17b0f5b7a..ff6938932 100644
--- a/src/core/Entry.cpp
+++ b/src/core/Entry.cpp
@@ -55,6 +55,7 @@ QIcon Entry::icon() const
         return DatabaseIcons::icon(m_iconNumber);
     }
     else {
+        // TODO check if m_db is 0
         return m_db->metadata()->customIcon(m_customIcon);
     }
 }
diff --git a/src/core/Entry.h b/src/core/Entry.h
index 303f12da8..b4a06051e 100644
--- a/src/core/Entry.h
+++ b/src/core/Entry.h
@@ -98,6 +98,9 @@ public:
     static bool isDefaultAttributue(const QString& key);
 
 Q_SIGNALS:
+    /**
+     * Emitted when a default attribute has been changed.
+     */
     void dataChanged(Entry* entry);
 
 private:
diff --git a/src/core/Group.cpp b/src/core/Group.cpp
index c83d38e9b..4e893caca 100644
--- a/src/core/Group.cpp
+++ b/src/core/Group.cpp
@@ -20,7 +20,6 @@
 
 #include "Group.h"
 
-#include "Database.h"
 #include "DatabaseIcons.h"
 #include "Metadata.h"
 
@@ -238,8 +237,6 @@ void Group::setParent(Database* db)
     recSetDatabase(db);
 
     QObject::setParent(db);
-
-    db->setRootGroup(this);
 }
 
 const Database* Group::database() const
diff --git a/src/core/Group.h b/src/core/Group.h
index ac37e9e39..4b49563d0 100644
--- a/src/core/Group.h
+++ b/src/core/Group.h
@@ -20,12 +20,11 @@
 
 #include <QtGui/QIcon>
 
+#include "Database.h"
 #include "Entry.h"
 #include "TimeInfo.h"
 #include "Uuid.h"
 
-class Database;
-
 class Group : public QObject
 {
     Q_OBJECT
@@ -63,15 +62,12 @@ public:
     Group* parentGroup();
     const Group* parentGroup() const;
     void setParent(Group* parent, int index = -1);
-    void setParent(Database* db);
 
     const Database* database() const;
     QList<Group*> children();
     const QList<Group*>& children() const;
     QList<Entry*> entries();
     const QList<Entry*>& entries() const;
-    void addEntry(Entry* entry);
-    void removeEntry(Entry* entry);
 
 Q_SIGNALS:
     void dataChanged(Group* group);
@@ -89,6 +85,10 @@ Q_SIGNALS:
     void entryDataChanged(Entry* entry);
 
 private:
+    void addEntry(Entry* entry);
+    void removeEntry(Entry* entry);
+    void setParent(Database* db);
+
     void recSetDatabase(Database* db);
 
     Database* m_db;
@@ -107,6 +107,9 @@ private:
     QList<Entry*> m_entries;
 
     Group* m_parent;
+
+    friend void Database::setRootGroup(Group* group);
+    friend void Entry::setGroup(Group *group);
 };
 
 #endif // KEEPASSX_GROUP_H
diff --git a/src/format/KeePass2XmlReader.cpp b/src/format/KeePass2XmlReader.cpp
index ba4877bec..aa2549218 100644
--- a/src/format/KeePass2XmlReader.cpp
+++ b/src/format/KeePass2XmlReader.cpp
@@ -21,6 +21,7 @@
 
 #include "core/Database.h"
 #include "core/DatabaseIcons.h"
+#include "core/Group.h"
 #include "core/Metadata.h"
 #include "format/KeePass2RandomStream.h"
 
@@ -40,7 +41,7 @@ void KeePass2XmlReader::readDatabase(QIODevice* device, Database* db, KeePass2Ra
     m_randomStream = randomStream;
 
     m_tmpParent = new Group();
-    m_tmpParent->setParent(m_db);
+    m_db->setRootGroup(m_tmpParent);
 
     if (!m_xml.error() && m_xml.readNextStartElement()) {
         if (m_xml.name() == "KeePassFile") {
@@ -276,7 +277,7 @@ void KeePass2XmlReader::parseRoot()
         if (m_xml.name() == "Group") {
             Group* rootGroup = parseGroup();
             if (rootGroup) {
-                rootGroup->setParent(m_db);
+                m_db->setRootGroup(rootGroup);
             }
         }
         else if (m_xml.name() == "DeletedObjects") {
diff --git a/src/format/KeePass2XmlWriter.h b/src/format/KeePass2XmlWriter.h
index bd21ed0a8..34e699b26 100644
--- a/src/format/KeePass2XmlWriter.h
+++ b/src/format/KeePass2XmlWriter.h
@@ -25,6 +25,7 @@
 
 #include "core/Database.h"
 #include "core/Entry.h"
+#include "core/Group.h"
 #include "core/TimeInfo.h"
 #include "core/Uuid.h"
 
diff --git a/tests/TestGroup.cpp b/tests/TestGroup.cpp
index 2a54d5f00..a5c0225f8 100644
--- a/tests/TestGroup.cpp
+++ b/tests/TestGroup.cpp
@@ -22,6 +22,7 @@
 #include <QtTest/QTest>
 
 #include "core/Database.h"
+#include "core/Group.h"
 
 void TestGroup::initTestCase()
 {
@@ -46,7 +47,7 @@ void TestGroup::testParenting()
     g2->setParent(g1);
     g4->setParent(g3);
     g3->setParent(g1);
-    g1->setParent(db);
+    db->setRootGroup(g1);
 
     QVERIFY(g1->parent() == db);
     QVERIFY(g2->parent() == g1);
@@ -91,7 +92,7 @@ void TestGroup::testSignals()
 {
     Database* db = new Database();
     QPointer<Group> root = new Group();
-    root->setParent(db);
+    db->setRootGroup(root);
 
     Group* g1 = new Group();
     Group* g2 = new Group();
diff --git a/tests/TestGroupModel.cpp b/tests/TestGroupModel.cpp
index 51c181f2b..96e2317fd 100644
--- a/tests/TestGroupModel.cpp
+++ b/tests/TestGroupModel.cpp
@@ -35,7 +35,7 @@ void TestGroupModel::test()
     Database* db = new Database();
 
     Group* groupRoot = new Group();
-    groupRoot->setParent(db);
+    db->setRootGroup(groupRoot);
     groupRoot->setName("groupRoot");
 
     Group* group1 = new Group();
diff --git a/tests/TestKeePass2Reader.cpp b/tests/TestKeePass2Reader.cpp
index a35a84d22..c41d42f34 100644
--- a/tests/TestKeePass2Reader.cpp
+++ b/tests/TestKeePass2Reader.cpp
@@ -21,6 +21,7 @@
 
 #include "config-keepassx-tests.h"
 #include "core/Database.h"
+#include "core/Group.h"
 #include "core/Metadata.h"
 #include "crypto/Crypto.h"
 #include "format/KeePass2Reader.h"
diff --git a/tests/TestKeePass2Writer.cpp b/tests/TestKeePass2Writer.cpp
index 72a351831..ba097d454 100644
--- a/tests/TestKeePass2Writer.cpp
+++ b/tests/TestKeePass2Writer.cpp
@@ -21,13 +21,13 @@
 #include <QtTest/QTest>
 
 #include "core/Database.h"
+#include "core/Group.h"
 #include "core/Metadata.h"
 #include "crypto/Crypto.h"
 #include "format/KeePass2Reader.h"
 #include "format/KeePass2Writer.h"
 #include "keys/PasswordKey.h"
 
-#include "format/KeePass2XmlWriter.h"
 void TestKeePass2Writer::initTestCase()
 {
     Crypto::init();
@@ -40,13 +40,12 @@ void TestKeePass2Writer::initTestCase()
     m_dbOrg->metadata()->setName("TESTDB");
     Group* group = new Group();
     group->setUuid(Uuid::random());
-    group->setParent(m_dbOrg);
     m_dbOrg->setRootGroup(group);
     Entry* entry = new Entry();
     entry->setUuid(Uuid::random());
     entry->addAttribute("test", "protectedTest", true);
     QVERIFY(entry->isAttributeProtected("test"));
-    group->addEntry(entry);
+    entry->setGroup(group);
 
     QBuffer buffer;
     buffer.open(QBuffer::ReadWrite);
diff --git a/tests/TestKeePass2XmlReader.cpp b/tests/TestKeePass2XmlReader.cpp
index c2dda9cf5..2678a464d 100644
--- a/tests/TestKeePass2XmlReader.cpp
+++ b/tests/TestKeePass2XmlReader.cpp
@@ -20,6 +20,7 @@
 #include <QtTest/QTest>
 
 #include "core/Database.h"
+#include "core/Group.h"
 #include "core/Metadata.h"
 #include "format/KeePass2XmlReader.h"
 #include "config-keepassx-tests.h"