diff --git a/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.h b/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.h
index b0cc6fb9d83..a479d108ca8 100644
--- a/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.h
+++ b/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.h
@@ -28,11 +28,11 @@
 #include <QListWidget>
 #include <QWidget>
 
-namespace Ui {
-class MesonBuildStepConfigWidget;
-}
 namespace MesonProjectManager {
 namespace Internal {
+
+namespace Ui { class MesonBuildStepConfigWidget; }
+
 class MesonBuildStepConfigWidget final : public ProjectExplorer::BuildStepConfigWidget
 {
     Q_DECLARE_TR_FUNCTIONS(MesonProjectManager::Internal::MesonBuildStepConfigWidget)
diff --git a/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.ui b/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.ui
index 1212227fb76..84f2e8171a3 100644
--- a/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.ui
+++ b/src/plugins/mesonprojectmanager/project/buildoptions/mesonbuildstepconfigwidget.ui
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ui version="4.0">
- <class>MesonBuildStepConfigWidget</class>
- <widget class="QWidget" name="MesonBuildStepConfigWidget">
+ <class>MesonProjectManager::Internal::MesonBuildStepConfigWidget</class>
+ <widget class="QWidget" name="MesonProjectManager::Internal::MesonBuildStepConfigWidget">
   <property name="geometry">
    <rect>
     <x>0</x>