diff --git a/src/plugins/projectexplorer/filewatcher.cpp b/src/plugins/projectexplorer/filewatcher.cpp
index eaf21cbd12e5c9feb565dd5048c7e82509e1e580..d513078e9b69af7d3b47e8b3ed597ccdb9c4adb8 100644
--- a/src/plugins/projectexplorer/filewatcher.cpp
+++ b/src/plugins/projectexplorer/filewatcher.cpp
@@ -84,7 +84,7 @@ void FileWatcher::addFile(const QString &file)
     const int count = ++m_fileCount[file];
     Q_ASSERT(count > 0);
 
-    m_files.insert(file, QDateTime());
+    m_files.insert(file, QFileInfo(file).lastModified());
 
     if (count == 1)
         m_watcher->addPath(file);