diff --git a/pkgs/tools/misc/tmux/default.nix b/pkgs/tools/misc/tmux/default.nix
index 4e5ca70b955..2043cfe1011 100644
--- a/pkgs/tools/misc/tmux/default.nix
+++ b/pkgs/tools/misc/tmux/default.nix
@@ -49,6 +49,8 @@ stdenv.mkDerivation rec {
     "--localstatedir=/var"
   ];
 
+  enableParallelBuilding = true;
+
   postInstall = ''
     mkdir -p $out/share/bash-completion/completions
     cp -v ${bashCompletion}/completions/tmux $out/share/bash-completion/completions/tmux