diff --git a/src/function.js b/src/function.js
index 80dce70..23c6436 100644
--- a/src/function.js
+++ b/src/function.js
@@ -152,3 +152,8 @@ export const repeat = curry((n, x) => {
   return results
 })
 
+export const tee = curry((f, x) => {
+  f(x)
+  return x
+})
+