diff --git a/src/mlp.c b/src/mlp.c
index dd3690dbd272b1648290db3a2f46bd1f9911fda1..f5f348123272fbad80a3ddeb9b4a31744f719c7c 100644
--- a/src/mlp.c
+++ b/src/mlp.c
@@ -74,7 +74,7 @@ static inline double tansig_approx(double x)
 	   x=-x;
 	   sign=-1;
 	}
-	i = lrint(25*x);
+	i = floor(.5+25*x);
 	x -= .04*i;
 	y = tansig_table[i];
 	dy = 1-y*y;