diff --git a/WFObj.hh b/WFObj.hh
index 65c5f58..3311142 100644
--- a/WFObj.hh
+++ b/WFObj.hh
@@ -22,7 +22,7 @@ protected:
 	{
 	public:
 		float operator[](int idx) const { return data[idx]; }
-		const float & operator[](int idx) { return data[idx]; }
+		float & operator[](int idx) { return data[idx]; }
 		float * getData() { return data; }
 	private:
 		float data[4];