diff --git a/README.md b/README.md
index 26a8af4..2aec81a 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,7 @@ lume.lerp(100, 200, .5) -- Returns 150
 ```
 
 ### lume.smooth(a, b, amount)
-Similar to `lume.lerp()` but uses cosine interpolation instead of linear
+Similar to `lume.lerp()` but uses cubic interpolation instead of linear
 interpolation.
 
 ### lume.pingpong(x)
diff --git a/lume.lua b/lume.lua
index d1d1985..e70c1cd 100644
--- a/lume.lua
+++ b/lume.lua
@@ -59,7 +59,8 @@ end
 
 
 function lume.smooth(a, b, amount)
-  local m = (1 - math_cos(lume.clamp(amount, 0, 1) * math_pi)) / 2
+  local t = lume.clamp(amount, 0, 1)
+  local m = t*t*(3-2*t)
   return a + (b - a) * m
 end