diff --git a/src/nvimage/Filter.h b/src/nvimage/Filter.h
index ae762f6..89b5606 100644
--- a/src/nvimage/Filter.h
+++ b/src/nvimage/Filter.h
@@ -78,7 +78,7 @@ namespace nv
 		MitchellFilter();
 		virtual float evaluate(float x) const;
 
-		void setParameters(float a, float b);
+		void setParameters(float b, float c);
 
 	private:
 		float p0, p2, p3;