diff --git a/pkgs/by-name/pl/plplot/package.nix b/pkgs/by-name/pl/plplot/package.nix
index 19ee4b47b317..b9edce149bcc 100644
--- a/pkgs/by-name/pl/plplot/package.nix
+++ b/pkgs/by-name/pl/plplot/package.nix
@@ -36,11 +36,13 @@ stdenv.mkDerivation rec {
     ];
 
   passthru = {
-    libX11 = libx11;
     inherit
       enableWX
       enableXWin
+      libx11
       ;
+    # backwards compat
+    libX11 = libx11;
   };
 
   cmakeFlags = [