diff --git a/src/core/Database.cpp b/src/core/Database.cpp
index 13dea7d1c..94113546d 100644
--- a/src/core/Database.cpp
+++ b/src/core/Database.cpp
@@ -275,6 +275,7 @@ bool Database::writeDatabase(QIODevice* device, QString* error)
         return false;
     }
 
+    QByteArray oldTransformedKey = m_data.transformedMasterKey;
     KeePass2Writer writer;
     setEmitModified(false);
     writer.writeDatabase(device, this);
@@ -288,6 +289,15 @@ bool Database::writeDatabase(QIODevice* device, QString* error)
         return false;
     }
 
+    Q_ASSERT(!m_data.transformedMasterKey.isEmpty());
+    Q_ASSERT(m_data.transformedMasterKey != oldTransformedKey);
+    if (m_data.transformedMasterKey.isEmpty() || m_data.transformedMasterKey == oldTransformedKey) {
+        if (error) {
+            *error = tr("Key not transformed. This is a bug, please report it to the developers!");
+        }
+        return false;
+    }
+
     markAsClean();
     return true;
 }
@@ -499,9 +509,11 @@ void Database::setCompressionAlgorithm(Database::CompressionAlgorithm algo)
  * @param key key to set and transform or nullptr to reset the key
  * @param updateChangedTime true to update database change time
  * @param updateTransformSalt true to update the transform salt
+ * @param transformKey trigger the KDF after setting the key
  * @return true on success
  */
-bool Database::setKey(const QSharedPointer<const CompositeKey>& key, bool updateChangedTime, bool updateTransformSalt)
+bool Database::setKey(const QSharedPointer<const CompositeKey>& key, bool updateChangedTime,
+        bool updateTransformSalt, bool transformKey)
 {
     Q_ASSERT(!m_data.isReadOnly);
 
@@ -519,7 +531,9 @@ bool Database::setKey(const QSharedPointer<const CompositeKey>& key, bool update
 
     QByteArray oldTransformedMasterKey = m_data.transformedMasterKey;
     QByteArray transformedMasterKey;
-    if (!key->transform(*m_data.kdf, transformedMasterKey)) {
+    if (!transformKey) {
+        transformedMasterKey = oldTransformedMasterKey;
+    } else if (!key->transform(*m_data.kdf, transformedMasterKey)) {
         return false;
     }
 
diff --git a/src/core/Database.h b/src/core/Database.h
index 84e2f90ef..8df2b9317 100644
--- a/src/core/Database.h
+++ b/src/core/Database.h
@@ -108,7 +108,8 @@ public:
     QSharedPointer<const CompositeKey> key() const;
     bool setKey(const QSharedPointer<const CompositeKey>& key,
                 bool updateChangedTime = true,
-                bool updateTransformSalt = false);
+                bool updateTransformSalt = false,
+                bool transformKey = true);
     QByteArray challengeResponseKey() const;
     bool challengeMasterSeed(const QByteArray& masterSeed);
     bool verifyKey(const QSharedPointer<CompositeKey>& key) const;
diff --git a/src/gui/dbsettings/DatabaseSettingsWidgetEncryption.cpp b/src/gui/dbsettings/DatabaseSettingsWidgetEncryption.cpp
index b536dfc71..80860673e 100644
--- a/src/gui/dbsettings/DatabaseSettingsWidgetEncryption.cpp
+++ b/src/gui/dbsettings/DatabaseSettingsWidgetEncryption.cpp
@@ -81,7 +81,7 @@ void DatabaseSettingsWidgetEncryption::initialize()
         isDirty = true;
     }
     if (!m_db->key()) {
-        m_db->setKey(QSharedPointer<CompositeKey>::create());
+        m_db->setKey(QSharedPointer<CompositeKey>::create(), true, false, false);
         m_db->setCipher(KeePass2::CIPHER_AES256);
         isDirty = true;
     }
diff --git a/src/gui/dbsettings/DatabaseSettingsWidgetMasterKey.cpp b/src/gui/dbsettings/DatabaseSettingsWidgetMasterKey.cpp
index a95f5b322..a8cff2c6d 100644
--- a/src/gui/dbsettings/DatabaseSettingsWidgetMasterKey.cpp
+++ b/src/gui/dbsettings/DatabaseSettingsWidgetMasterKey.cpp
@@ -190,9 +190,13 @@ bool DatabaseSettingsWidgetMasterKey::save()
         }
     }
 
-    m_db->setKey(newKey);
+    m_db->setKey(newKey, true, false, false);
 
     emit editFinished(true);
+    if (m_isDirty) {
+        m_db->markAsModified();
+    }
+
     return true;
 }