diff --git a/sfx2/source/control/thumbnailview.cxx b/sfx2/source/control/thumbnailview.cxx
index f73b364cbe41..39b1ce8f0511 100644
--- a/sfx2/source/control/thumbnailview.cxx
+++ b/sfx2/source/control/thumbnailview.cxx
@@ -529,7 +529,9 @@ void ThumbnailView::KeyInput( const KeyEvent& rKEvt )
     {
         //If the last elemented selected is the start range position
         //search for the first selected item
-        if (nLastPos == mpStartSelRange - mFilteredItemList.begin())
+        size_t nSelPos = mpStartSelRange - mFilteredItemList.begin();
+
+        if (nLastPos == nSelPos)
         {
             while (nLastPos && mFilteredItemList[nLastPos-1]->isSelected())
                 --nLastPos;