diff --git a/stdlib/float.mc b/stdlib/float.mc
index 43ab3f2d7..cc9fb6a70 100644
--- a/stdlib/float.mc
+++ b/stdlib/float.mc
@@ -27,3 +27,13 @@ utest maxf 1. 0. with 1.
 utest maxf 0. 1. with 1.
 utest isNaN (maxf nan 0.) with true
 utest isNaN (maxf 0. nan) with true
+
+
+-- `absf a` returns the absolute value of `a` or `nan` if `a` is `nan`.
+let absf: Float -> Float = lam f. maxf f (negf f)
+
+utest absf 0. with 0. using eqf
+utest absf 1. with 1. using eqf
+utest absf -1. with 1. using eqf
+utest absf -0. with 0. using eqf
+utest isNaN (absf nan) with true
diff --git a/stdlib/math.mc b/stdlib/math.mc
index 432ab05ca..5868a148f 100644
--- a/stdlib/math.mc
+++ b/stdlib/math.mc
@@ -8,10 +8,6 @@ utest minf 0. 0. with 0. using eqf
 utest minf 1. 0. with 0. using eqf
 utest minf 0. 1. with 0. using eqf
 
-utest absf 0. with 0. using eqf
-utest absf 1. with 1. using eqf
-utest absf (negf 1.) with 1. using eqf
-
 let cmpfApprox : Float -> Float -> Float -> Int =
   lam epsilon. lam l. lam r.
     if eqfApprox epsilon l r then 0