diff --git a/pkgs/lib/trivial.nix b/pkgs/lib/trivial.nix
index 4b99ad8c72c..35e4f3ee9f9 100644
--- a/pkgs/lib/trivial.nix
+++ b/pkgs/lib/trivial.nix
@@ -15,4 +15,6 @@ rec {
   # Take a function and evaluate it with its own returned value.
   fix = f: let result = f result; in result;
 
+  # Flip argument order
+  flip = f: x: y: f y x;
 }