diff --git a/pkgs/applications/misc/rxvt_unicode-plugins/urxvt-font-size/default.nix b/pkgs/applications/misc/rxvt_unicode-plugins/urxvt-font-size/default.nix
index eafa0d6d18b8..bca87b12b9f2 100644
--- a/pkgs/applications/misc/rxvt_unicode-plugins/urxvt-font-size/default.nix
+++ b/pkgs/applications/misc/rxvt_unicode-plugins/urxvt-font-size/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, xrdb }:
+{ stdenv, fetchFromGitHub, xrdb, xlsfonts }:
 
 stdenv.mkDerivation {
   name = "urxvt-font-size-2015-05-22";
@@ -13,7 +13,8 @@ stdenv.mkDerivation {
 
   installPhase = ''
     substituteInPlace font-size \
-      --replace "xrdb -merge" "${xrdb}/bin/xrdb -merge"
+      --replace "xrdb -merge" "${xrdb}/bin/xrdb -merge" \
+      --replace "xlsfonts" "${xlsfonts}/bin/xlsfonts"
 
     mkdir -p $out/lib/urxvt/perl
     cp font-size $out/lib/urxvt/perl