diff --git a/lib/contrast.c b/lib/contrast.c
index b1c9fa7..7bc4644 100644
--- a/lib/contrast.c
+++ b/lib/contrast.c
@@ -60,7 +60,7 @@ for (idx=0; idx<nbre; idx++) {
 	d->B[idx] = maxval * sqrt(dval);
 	}
 
-return -1;
+return 0;
 }
 /* ---------------------------------------------------------------- */
 int fimg_power_2(FloatImg *s, FloatImg *d, double maxval)