diff --git a/ApplicationCode/UserInterface/RiuWidgetStyleSheet.cpp b/ApplicationCode/UserInterface/RiuWidgetStyleSheet.cpp
index c0bdb407f0..c97cf8efd7 100644
--- a/ApplicationCode/UserInterface/RiuWidgetStyleSheet.cpp
+++ b/ApplicationCode/UserInterface/RiuWidgetStyleSheet.cpp
@@ -125,6 +125,8 @@ RiuWidgetStyleSheet::State& RiuWidgetStyleSheet::state( StateTag stateTag )
 //--------------------------------------------------------------------------------------------------
 void RiuWidgetStyleSheet::applyToWidget( QWidget* widget ) const
 {
+    CAF_ASSERT( !widget->objectName().isEmpty() &&
+                "The widget is required to have an object name set with setObjectName" );
     QString completeStyleSheet = fullText( QString( widget->metaObject()->className() ), widget->objectName() );
     // qDebug().noquote() << completeStyleSheet;
     widget->setStyleSheet( completeStyleSheet );
diff --git a/ApplicationCode/UserInterface/RiuWidgetStyleSheet.h b/ApplicationCode/UserInterface/RiuWidgetStyleSheet.h
index 7a2b204e58..43c2da1266 100644
--- a/ApplicationCode/UserInterface/RiuWidgetStyleSheet.h
+++ b/ApplicationCode/UserInterface/RiuWidgetStyleSheet.h
@@ -27,9 +27,8 @@ class RiuWidgetStyleSheetManager;
 class QWidget;
 
 //==================================================================================================
-//
-//
-//
+// ResInsight widget class. Meant to create and apply style sheets to particular widget instances.
+// without "bleeding" the look into other widgets.
 //==================================================================================================
 class RiuWidgetStyleSheet
 {