diff --git a/nixos/modules/programs/shadow.nix b/nixos/modules/programs/shadow.nix
index fab809f279a3..35267acd6bb7 100644
--- a/nixos/modules/programs/shadow.nix
+++ b/nixos/modules/programs/shadow.nix
@@ -41,6 +41,8 @@ let
       # This should be made configurable.
       #CHFN_RESTRICT frwh
 
+      # The default crypt() method, keep in sync with the PAM default
+      ENCRYPT_METHOD YESCRYPT
     '';
 
   mkSetuidRoot = source: