diff --git a/src/plugins/python/pythonproject.cpp b/src/plugins/python/pythonproject.cpp
index 50ffe379943..c9bb0f0b6ce 100644
--- a/src/plugins/python/pythonproject.cpp
+++ b/src/plugins/python/pythonproject.cpp
@@ -302,12 +302,21 @@ bool PythonBuildSystem::addFiles(Node *, const FilePaths &filePaths, FilePaths *
 {
     const Utils::FilePath projectDir = projectDirectory();
 
+    auto comp = [](const FileEntry &left, const FileEntry &right) {
+        return left.rawEntry < right.rawEntry;
+    };
+
+    const bool isSorted = std::is_sorted(m_files.begin(), m_files.end(), comp);
+
     for (const FilePath &filePath : filePaths) {
         if (!projectDir.isSameDevice(filePath))
             return false;
         m_files.append(FileEntry{filePath.relativePathFrom(projectDir).toString(), filePath});
     }
 
+    if (isSorted)
+        std::sort(m_files.begin(), m_files.end(), comp);
+
     return save();
 }