diff --git a/lib/customisation.nix b/lib/customisation.nix
index 18d94f2b8cf5..aaf0cf20fc9b 100644
--- a/lib/customisation.nix
+++ b/lib/customisation.nix
@@ -764,6 +764,7 @@ rec {
 
       `inheritFunctionArgs` (default to `true`)
       : Whether to inherit `__functionArgs` from the base build helper.
+        Set `inheritFunctionArgs` to `false` when `extendDrvArgs`'s `args` set pattern does not contain an ellipsis.
 
       `transformDrv` (default to `lib.id`)
       : Function to apply to the result derivation.