diff --git a/src/toolbars/SpectralSelectionBar.cpp b/src/toolbars/SpectralSelectionBar.cpp
index 8ddbb0d1f..12fec1d2b 100644
--- a/src/toolbars/SpectralSelectionBar.cpp
+++ b/src/toolbars/SpectralSelectionBar.cpp
@@ -369,7 +369,15 @@ void SpectralSelectionBar::OnChoice(wxCommandEvent &)
    GetSizer()->Layout();   // Required so that the layout does not mess up on Windows when changing the format.
    wxWindowBase::GetSizer()->SetMinSize(wxSize(0, mHeight));   // so that height of toolbar does not change
    wxWindowBase::GetSizer()->SetSizeHints(this);
-   Updated();
+   if( IsDocked() )
+      Updated();
+   else {
+      // Bug 2120.  Changing the choice also changes the size of the toolbar so
+      // we need to update the client size, even if undocked.
+      // If attempting to make this code nicer, remember to test both changing the choice,
+      // and the choice remaining the same.
+      GetParent()->SetClientSize( GetSize() + wxSize( 2,2));
+   }
 }
 
 void SpectralSelectionBar::OnIdle( wxIdleEvent &evt )