diff --git a/src/plugins/cppeditor/cppeditor.cpp b/src/plugins/cppeditor/cppeditor.cpp
index fe072bde82a448fec861c4df6c7856519e1ce491..331c66946ce462483cb4a51312593efd5278289e 100644
--- a/src/plugins/cppeditor/cppeditor.cpp
+++ b/src/plugins/cppeditor/cppeditor.cpp
@@ -709,7 +709,7 @@ void CPPEditorWidget::setMimeType(const QString &mt)
     const QString &projectFile = ProjectExplorer::SessionManager::value(
                 QLatin1String(Constants::CPP_PREPROCESSOR_PROJECT_PREFIX) + filePath).toString();
     const QByteArray &additionalDirectives = ProjectExplorer::SessionManager::value(
-                projectFile + QLatin1Char(',') + filePath).toByteArray();
+                projectFile + QLatin1Char(',') + filePath).toString().toUtf8();
 
     QSharedPointer<SnapshotUpdater> updater
             = m_modelManager->cppEditorSupport(editor())->snapshotUpdater();
@@ -1988,7 +1988,7 @@ void CPPEditorWidget::showPreProcessorWidget()
     if (preProcessorDialog.exec() == QDialog::Accepted) {
         QSharedPointer<SnapshotUpdater> updater
                 = m_modelManager->cppEditorSupport(editor())->snapshotUpdater();
-        updater->setEditorDefines(preProcessorDialog.additionalPreProcessorDirectives().toLatin1());
+        updater->setEditorDefines(preProcessorDialog.additionalPreProcessorDirectives().toUtf8());
         updater->update(m_modelManager->workingCopy());
     }
 }
diff --git a/src/plugins/cpptools/cppmodelmanager_test.cpp b/src/plugins/cpptools/cppmodelmanager_test.cpp
index 3d1383b46956bb4d3461649e92d7243b473e90fc..a7a6aa222e0ed2f9b151f40a3ef4fcea1d33a1c4 100644
--- a/src/plugins/cpptools/cppmodelmanager_test.cpp
+++ b/src/plugins/cpptools/cppmodelmanager_test.cpp
@@ -1000,7 +1000,7 @@ void CppToolsPlugin::test_modelmanager_defines_per_editor()
         while (sup->lastSemanticInfoDocument().isNull())
             QCoreApplication::processEvents();
 
-        sup->snapshotUpdater()->setEditorDefines(editorDefines.toLatin1());
+        sup->snapshotUpdater()->setEditorDefines(editorDefines.toUtf8());
         sup->snapshotUpdater()->update(mm->workingCopy());
 
         Document::Ptr doc = mm->snapshot().document(main1File);