diff --git a/pkgs/development/tools/rubyfmt/default.nix b/pkgs/development/tools/rubyfmt/default.nix
index 15457e80aad9..756340e3f091 100644
--- a/pkgs/development/tools/rubyfmt/default.nix
+++ b/pkgs/development/tools/rubyfmt/default.nix
@@ -13,6 +13,7 @@
 , libunwind
 , libxcrypt
 , libyaml
+, rust-jemalloc-sys-unprefixed
 , Foundation
 , Security
 }:
@@ -40,6 +41,7 @@ rustPlatform.buildRustPackage rec {
     zlib
     libxcrypt
     libyaml
+    rust-jemalloc-sys-unprefixed
   ] ++ lib.optionals stdenv.isDarwin [
     readline
     libiconv