diff --git a/pkgs/development/r-modules/default.nix b/pkgs/development/r-modules/default.nix
index 038fc761baec..247d303875bf 100644
--- a/pkgs/development/r-modules/default.nix
+++ b/pkgs/development/r-modules/default.nix
@@ -1195,7 +1195,7 @@ let
     });
 
     b64 = old.b64.overrideAttrs (attrs: {
-      nativeBuildInputs = [ pkgs.cargo ] ++ attrs.nativeBuildInputs;
+      nativeBuildInputs = with pkgs; [ cargo rustc ] ++ attrs.nativeBuildInputs;
       postPatch = "patchShebangs configure";
     });