diff --git a/src/plugins/cppeditor/cppmodelmanager.cpp b/src/plugins/cppeditor/cppmodelmanager.cpp
index 231740899be..cc08724373d 100644
--- a/src/plugins/cppeditor/cppmodelmanager.cpp
+++ b/src/plugins/cppeditor/cppmodelmanager.cpp
@@ -1660,7 +1660,6 @@ QList<ProjectPart::ConstPtr> CppModelManager::projectPartFromDependencies(
     QSet<ProjectPart::ConstPtr> parts;
     const FilePaths deps = snapshot().filesDependingOn(fileName);
 
-    QReadLocker locker(&d->m_projectLock);
     for (const FilePath &dep : deps)
         parts.unite(Utils::toSet(projectPart(dep)));