diff --git a/lib/fileset/default.nix b/lib/fileset/default.nix
index acb7ac10c237..17393a81860f 100644
--- a/lib/fileset/default.nix
+++ b/lib/fileset/default.nix
@@ -703,7 +703,7 @@ in
     # Type
 
     ```
-    union :: FileSet -> FileSet -> FileSet
+    difference :: FileSet -> FileSet -> FileSet
     ```
 
     # Examples