diff --git a/pkgs/tools/security/doas/default.nix b/pkgs/tools/security/doas/default.nix
index 29c23bbef279..489bf2bb2aa3 100644
--- a/pkgs/tools/security/doas/default.nix
+++ b/pkgs/tools/security/doas/default.nix
@@ -3,6 +3,7 @@
 , fetchFromGitHub
 , bison
 , pam
+, libxcrypt
 
 , withPAM ? true
 , withTimestamp ? true
@@ -38,7 +39,9 @@ stdenv.mkDerivation rec {
   '';
 
   nativeBuildInputs = [ bison ];
-  buildInputs = [ pam ];
+  buildInputs = [ ]
+    ++ lib.optional withPAM pam
+    ++ lib.optional (!withPAM) libxcrypt;
 
   meta = with lib; {
     description = "Executes the given command as another user";