diff --git a/pkgs/applications/networking/instant-messengers/tkabber/default.nix b/pkgs/applications/networking/instant-messengers/tkabber/default.nix
index 03a98cb2059..fd989739c94 100644
--- a/pkgs/applications/networking/instant-messengers/tkabber/default.nix
+++ b/pkgs/applications/networking/instant-messengers/tkabber/default.nix
@@ -36,6 +36,7 @@ in stdenv.mkDerivation rec {
 
   postInstall = ''
     wrapProgram $out/bin/tkabber \
+      --prefix PATH : "${tk}/bin" \
       --set TCLLIBPATH '"${tclLibPaths}"' \
       --set TKABBER_SITE_PLUGINS '$HOME/.nix-profile/share/tkabber-plugins'
   '';