diff --git a/README.md b/README.md
index 207e5d8..d292d8e 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,9 @@ data has been migrated.
 
 - Source Machine:
 
-  - Can be any Linux machine with Nix installed, or a NixOS machine.
+  - Can be any machine with Nix installed, e.g. a NixOS machine.
+  - Should be able to build nix derivations for the target platform. Otherwise
+    `--build-on-remote` can be used.
 
 - Target Machine: