diff --git a/src/ATBAPP/support/PersistentData.cpp b/src/ATBAPP/support/PersistentData.cpp
index cfcf305..e3b70ce 100644
--- a/src/ATBAPP/support/PersistentData.cpp
+++ b/src/ATBAPP/support/PersistentData.cpp
@@ -30,7 +30,10 @@ PersistentData::PersistentData(const QString &datafileName, QObject *parent)
 
 void PersistentData::serializeToFile()
 {
-    this->save();
+    if (this->isChangedFlag) {
+        qCritical() << "PersistentData::isChanged -> save";
+        this->save();
+    }
 }
 
 void PersistentData::save()
@@ -44,6 +47,8 @@ void PersistentData::save()
         out << this->hash;
         fileOut.flush();
         fileOut.close();
+
+        this->isChangedFlag = false;
     }
 }