diff --git a/pdfminer/converter.py b/pdfminer/converter.py
index e9c2d79..9bd4bef 100644
--- a/pdfminer/converter.py
+++ b/pdfminer/converter.py
@@ -128,7 +128,7 @@ class PDFPageAggregator(PDFTextDevice):
       (x0,y0) = apply_matrix_pt(self.ctm, (x0,y0))
       (x1,y1) = apply_matrix_pt(self.ctm, (x1,y1))
       (x2,y2) = apply_matrix_pt(self.ctm, (x2,y2))
-      (x3,y3) = apply_matrix_pt(self.ctm, (x3,y2))
+      (x3,y3) = apply_matrix_pt(self.ctm, (x3,y3))
       if ((x0 == x1 and y1 == y2 and x2 == x3 and y3 == y0) or
           (y0 == y1 and x1 == x2 and y2 == y3 and x3 == x0)):
         self.cur_item.add(LTRect(gstate.linewidth, (x0,y0,x2,y2)))