diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 200d3b0a..cd483e47 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -1978,6 +1978,7 @@ void FurnaceGUI::doDelete() {
       for (int j=selStart.y; j<=selEnd.y; j++) {
         if (iFine==0) {
           pat->data[j][iFine]=0;
+          if (selStart.y==selEnd.y) pat->data[j][2]=-1;
         }
         pat->data[j][iFine+1]=(iFine<1)?0:-1;
       }