diff --git a/modules/packages/desktop/default.nix b/modules/packages/desktop/default.nix
index 4eeb1526..45a40e6d 100644
--- a/modules/packages/desktop/default.nix
+++ b/modules/packages/desktop/default.nix
@@ -72,7 +72,7 @@ inputs:
           inputs.pkgs."pkgs-23.11".gnuplot
           # math, physics and chemistry
           octaveFull root ovito localPackages.vesta localPackages.v-sim
-          (mathematica.overrideAttrs (prev: { postInstall = prev.postInstall or "" + "ln -s ${src} $out/src"; }))
+          (mathematica.overrideAttrs (prev: { postInstall = (prev.postInstall or "") + "ln -s ${prev.src} $out/src"; }))
           (quantum-espresso.override { stdenv = gcc14Stdenv; gfortran = gfortran14; }) jmol mpi localPackages.ufo
           # virtualization
           wineWowPackages.stagingFull virt-viewer bottles genymotion playonlinux