diff --git a/apps/opencs/view/render/terraintexturemode.cpp b/apps/opencs/view/render/terraintexturemode.cpp
index 6d682150a..40dfc9474 100644
--- a/apps/opencs/view/render/terraintexturemode.cpp
+++ b/apps/opencs/view/render/terraintexturemode.cpp
@@ -730,8 +730,12 @@ void CSVRender::TerrainTextureMode::setBrushShape(int brushShape)
             selectionCenterY += value.second;
             ++selectionAmount;
         }
-        selectionCenterX /= selectionAmount;
-        selectionCenterY /= selectionAmount;
+
+        if (selectionAmount != 0)
+        {
+            selectionCenterX /= selectionAmount;
+            selectionCenterY /= selectionAmount;
+        }
 
         mCustomBrushShape.clear();
         for (auto const& value: terrainSelection)