diff --git a/pkgs/tools/networking/p2p/rtorrent/default.nix b/pkgs/tools/networking/p2p/rtorrent/default.nix
index d702e3b9700f..ccb004ffb8c8 100644
--- a/pkgs/tools/networking/p2p/rtorrent/default.nix
+++ b/pkgs/tools/networking/p2p/rtorrent/default.nix
@@ -12,7 +12,7 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [ libtorrent ncurses pkgconfig libsigcxx curl zlib openssl xmlrpc_c ];
-  configureFlags = "--with-xmlrpc-c";
+  configureFlags = [ "--with-xmlrpc-c" "--with-posix-fallocate" ];
 
   # postInstall = ''
   #   mkdir -p $out/share/man/man1 $out/share/rtorrent