diff --git a/src/gui/painting/qregion.cpp b/src/gui/painting/qregion.cpp
index 7acfceee8d5..df1f2575fe7 100644
--- a/src/gui/painting/qregion.cpp
+++ b/src/gui/painting/qregion.cpp
@@ -3572,6 +3572,8 @@ static QRegionPrivate *PolygonRegion(const QPoint *Pts, int Count, int rule)
     POINTBLOCK *tmpPtBlock;
     int numFullPtBlocks = 0;
 
+    Q_ASSUME(Count > 1);
+
     region = new QRegionPrivate;
 
         /* special case a rectangle */