diff --git a/include/wx/generic/gridsel.h b/include/wx/generic/gridsel.h
index d613283f66..08377e3b08 100644
--- a/include/wx/generic/gridsel.h
+++ b/include/wx/generic/gridsel.h
@@ -68,9 +68,11 @@ public:
     void UpdateCols( size_t pos, int numCols );
 
     // Extend (or shrink) the current selection block (creating it if
-    // necessary, i.e. if there is no selection at all currently) to the one
-    // specified by the start and end coordinates of its opposite corners
-    // (which don't have to be in top/bottom left/right order).
+    // necessary, i.e. if there is no selection at all currently or if the
+    // current current cell isn't selected, as in this case a new block
+    // containing it is always added) to the one specified by the start and end
+    // coordinates of its opposite corners (which don't have to be in
+    // top/bottom left/right order).
     //
     // Note that blockStart is equal to wxGrid::m_currentCellCoords almost
     // always, but not always (the exception is when we scrolled out from
diff --git a/src/generic/gridsel.cpp b/src/generic/gridsel.cpp
index d4953c59d2..fc41b359bd 100644
--- a/src/generic/gridsel.cpp
+++ b/src/generic/gridsel.cpp
@@ -496,7 +496,11 @@ bool wxGridSelection::ExtendCurrentBlock(const wxGridCellCoords& blockStart,
     wxASSERT( blockStart.GetRow() != -1 && blockStart.GetCol() != -1 &&
               blockEnd.GetRow() != -1 && blockEnd.GetCol() != -1 );
 
-    if ( m_selection.empty() )
+    // If selection doesn't contain the current cell (which also covers the
+    // special case of nothing being selected yet), we have to create a new
+    // block containing it because it doesn't make sense to extend any existing
+    // block to non-selected current cell.
+    if ( !IsInSelection(m_grid->GetGridCursorCoords()) )
     {
         SelectBlock(blockStart, blockEnd);
         return true;
@@ -649,7 +653,10 @@ wxGridCellCoords wxGridSelection::GetExtensionAnchor() const
 {
     wxGridCellCoords coords = m_grid->m_currentCellCoords;
 
-    if ( m_selection.empty() )
+    // If the current cell isn't selected (which also covers the special case
+    // of nothing being selected yet), we have to use it as anchor as we need
+    // to ensure that it will get selected.
+    if ( !IsInSelection(coords) )
         return coords;
 
     const wxGridBlockCoords& block = *m_selection.rbegin();