diff --git a/src/plugins/coreplugin/locator/filesystemfilter.cpp b/src/plugins/coreplugin/locator/filesystemfilter.cpp
index f7f6f906773..3402e69b792 100644
--- a/src/plugins/coreplugin/locator/filesystemfilter.cpp
+++ b/src/plugins/coreplugin/locator/filesystemfilter.cpp
@@ -44,10 +44,11 @@
 #include <QPushButton>
 #include <QRegularExpression>
 
-using namespace Core;
-using namespace Core::Internal;
 using namespace Utils;
 
+namespace Core {
+namespace Internal {
+
 ILocatorFilter::MatchLevel FileSystemFilter::matchLevelFor(const QRegularExpressionMatch &match,
                                                            const QString &matchText)
 {
@@ -159,8 +160,7 @@ QList<LocatorFilterEntry> FileSystemFilter::matchesFor(QFutureInterface<LocatorF
                                          tr("Create and Open \"%1\"").arg(entry),
                                          fullFilePath);
         createAndOpen.filePath = FilePath::fromString(fullFilePath);
-        createAndOpen.extraInfo = Utils::FilePath::fromString(dirInfo.absolutePath())
-                                      .shortNativePath();
+        createAndOpen.extraInfo = FilePath::fromString(dirInfo.absolutePath()).shortNativePath();
         entries[int(MatchLevel::Normal)].append(createAndOpen);
     }
 
@@ -186,13 +186,13 @@ void FileSystemFilter::accept(LocatorFilterEntry selection,
         QMetaObject::invokeMethod(EditorManager::instance(), [info, selection] {
             const QString targetFile = selection.internalData.toString();
             if (!info.exists()) {
-                if (Utils::CheckableMessageBox::shouldAskAgain(ICore::settings(), kAlwaysCreate)) {
-                    Utils::CheckableMessageBox messageBox(ICore::dialogParent());
+                if (CheckableMessageBox::shouldAskAgain(ICore::settings(), kAlwaysCreate)) {
+                    CheckableMessageBox messageBox(ICore::dialogParent());
                     messageBox.setWindowTitle(tr("Create File"));
                     messageBox.setIcon(QMessageBox::Question);
                     messageBox.setText(
                         tr("Create \"%1\"?")
-                            .arg(Utils::FilePath::fromString(targetFile).shortNativePath()));
+                            .arg(FilePath::fromString(targetFile).shortNativePath()));
                     messageBox.setCheckBoxVisible(true);
                     messageBox.setCheckBoxText(tr("Always create"));
                     messageBox.setChecked(false);
@@ -204,7 +204,7 @@ void FileSystemFilter::accept(LocatorFilterEntry selection,
                     if (messageBox.clickedButton() != createButton)
                         return;
                     if (messageBox.isChecked())
-                        Utils::CheckableMessageBox::doNotAskAgain(ICore::settings(), kAlwaysCreate);
+                        CheckableMessageBox::doNotAskAgain(ICore::settings(), kAlwaysCreate);
                 }
                 QFile file(targetFile);
                 file.open(QFile::WriteOnly);
@@ -273,3 +273,6 @@ void FileSystemFilter::restoreState(const QByteArray &state)
         ILocatorFilter::restoreState(state);
     }
 }
+
+} // Internal
+} // Core