diff --git a/pkgs/development/libraries/tclx/default.nix b/pkgs/development/libraries/tclx/default.nix
index 27602684c171..a8cf2a44fab6 100644
--- a/pkgs/development/libraries/tclx/default.nix
+++ b/pkgs/development/libraries/tclx/default.nix
@@ -12,7 +12,7 @@ tcl.mkTclDerivation rec {
 
   # required in order for tclx to properly detect tclx.tcl at runtime
   postInstall = ''
-    ln -s $prefix/lib/${tclXPkg} $prefix/lib/tclx${version}/tclx${version}
+    ln -s $prefix/lib/tclx${version} $prefix/lib/tclx${version}/tclx${version}
   '';
 
   meta = {