diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 5900487c..ebed896a 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -132,9 +132,10 @@
   Dense DAISY feature description, circle perimeter drawing.
 
 - François Boulogne
-  Drawing: Andres Method for circle perimeter, ellipse perimeter drawing,
+  Drawing: Andres Method for circle perimeter, ellipse perimeter,
   Bezier curve, anti-aliasing.
   Circular and elliptical Hough Transforms
+  Thresholding
   Various fixes
 
 - Thouis Jones