diff --git a/pkgs/development/r-modules/default.nix b/pkgs/development/r-modules/default.nix
index 6ffacbd75f4c..b0ded1f2a06f 100644
--- a/pkgs/development/r-modules/default.nix
+++ b/pkgs/development/r-modules/default.nix
@@ -557,7 +557,7 @@ let
     island = [ pkgs.gsl.dev ];
     svKomodo = [ pkgs.which ];
     ulid = [ pkgs.zlib.dev ];
-    unrtf = with pkgs; [ xz.dev bzip2.dev zlib.dev icu.dev ];
+    unrtf = with pkgs; [ xz.dev bzip2.dev zlib.dev icu.dev libdeflate ];
     nat = [ pkgs.which ];
     nat_templatebrains = [ pkgs.which ];
     pbdZMQ = [ pkgs.zeromq ] ++ lib.optionals stdenv.isDarwin [ pkgs.darwin.binutils ];