diff --git a/install_spack_env.sh b/install_spack_env.sh
index 2cb37f4501375909e9abab11b1efa89b28b97ca1..96c17f52014443e657c3e8847bf07655aa380a5f 100644
--- a/install_spack_env.sh
+++ b/install_spack_env.sh
@@ -22,7 +22,7 @@ then
   git clone --depth 1 -c advice.detachedHead=false -c feature.manyFiles=true --branch $SPACK_VERSION https://github.com/spack/spack $INSTALLATION_ROOT/spack
 fi
 # SPACK PATCH: see https://github.com/spack/spack/pull/35290
-sed -i 's/solver.solve(abstract_specs)/solver.solve(abstract_specs, tests=kwargs.get("tests", False))/g' $SPACK_PATH/lib/spack/spack/concretize.py
+sed -i 's/solver.solve(abstract_specs)/solver.solve(abstract_specs, tests=kwargs.get("tests", False))/g' $INSTALLATION_ROOT/spack/lib/spack/spack/concretize.py
 
 cp $EBRAINS_REPO/packages.yaml $INSTALLATION_ROOT/spack/etc/spack/packages.yaml
 source $INSTALLATION_ROOT/spack/share/spack/setup-env.sh