diff --git a/cxx/cucul++.cpp b/cxx/cucul++.cpp
index e80d838..fa35ff1 100644
--- a/cxx/cucul++.cpp
+++ b/cxx/cucul++.cpp
@@ -323,11 +323,6 @@ void Dither::setContrast(float f)
     cucul_set_dither_contrast(dither, f);
 }
 
-void Dither::setInvert(int i)
-{
-    cucul_set_dither_invert(dither, i);
-}
-
 void Dither::setAntialias(char const *cv)
 {
     cucul_set_dither_antialias(dither, cv);
diff --git a/cxx/cucul++.h b/cxx/cucul++.h
index e4d9d55..be1e7b3 100644
--- a/cxx/cucul++.h
+++ b/cxx/cucul++.h
@@ -65,7 +65,6 @@ class Dither
     void setBrightness(float);
     void setGamma(float);
     void setContrast(float);
-    void setInvert(int);
     void setAntialias(char const *);
     char const *const * getAntialiasList();
     void setColor(char const *);
diff --git a/test/demo.c b/test/demo.c
index a0262e0..57367bf 100644
--- a/test/demo.c
+++ b/test/demo.c
@@ -555,7 +555,7 @@ static void demo_render(void)
         draw_circle(buffer, xo, yo, z, 0x000000ff, 200);
 
     dither = cucul_create_dither(32, 256, 256, 4 * 256, 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
- cucul_set_dither_invert(dither, 1);
+    cucul_set_dither_gamma(dither, -1.0);
     cucul_dither_bitmap(cv, 0, 0, cucul_get_canvas_width(cv), cucul_get_canvas_height(cv), dither, (char *)buffer);
     cucul_free_dither(dither);
 }