diff --git a/src/libsync/logger.cpp b/src/libsync/logger.cpp
index 5e885d7afebe4..7d1925d5ad648 100644
--- a/src/libsync/logger.cpp
+++ b/src/libsync/logger.cpp
@@ -37,6 +37,7 @@ namespace {
 
 constexpr int CrashLogSize = 20;
 constexpr auto MaxLogLinesCount = 50000;
+constexpr auto MaxLogLinesBeforeFlush = 10;
 
 static bool compressLog(const QString &originalName, const QString &targetName)
 {
@@ -145,8 +146,11 @@ void Logger::doLog(QtMsgType type, const QMessageLogContext &ctx, const QString
 
         if (_logstream) {
             (*_logstream) << msg << "\n";
-            if (_doFileFlush)
+            ++_linesCounter;
+            if (_doFileFlush || _linesCounter >= MaxLogLinesBeforeFlush) {
                 _logstream->flush();
+                _linesCounter = 0;
+            }
         }
         if (_permanentDeleteLogStream && ctx.category && strcmp(ctx.category, lcPermanentLog().categoryName()) == 0) {
             (*_permanentDeleteLogStream) << msg << "\n";
diff --git a/src/libsync/logger.h b/src/libsync/logger.h
index 2d9dce3193edd..b913678b40172 100644
--- a/src/libsync/logger.h
+++ b/src/libsync/logger.h
@@ -110,6 +110,7 @@ public slots:
 
     QFile _logFile;
     bool _doFileFlush = false;
+    int _linesCounter = 0;
     int _logExpire = 0;
     bool _logDebug = false;
     QScopedPointer<QTextStream> _logstream;