diff --git a/include/lustrec_math.lusi b/include/lustrec_math.lusi
index ffbdd2aeea07a21655b0fc36d5bf5f94415627fe..5e8d79c43be7ad6d03983c4202f0cc5000ff339f 100644
--- a/include/lustrec_math.lusi
+++ b/include/lustrec_math.lusi
@@ -11,8 +11,12 @@ function cosh (x: real) returns (y: real) prototype C lib m;
 function ceil (x: real) returns (y: real) prototype C lib m;
 function erf (x: real) returns (y: real) prototype C lib m;
 function fabs (x: real) returns (y: real) prototype C lib m;
+function floor (x: real) returns (y: real) prototype C lib m;
 function tan (x: real) returns (y: real) prototype C lib m;
 function pow (x:real; n: real) returns (y: real) prototype C lib m;
+function round (x: real) returns (y: real) prototype C lib m;
 function sin (x: real) returns (y: real) prototype C lib m;
 function sinh (x: real) returns (y: real) prototype C lib m;
 function sqrt (x: real) returns (y: real) prototype C lib m;
+function trunc (x: real) returns (y: real) prototype C lib m;
+