diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1443195b994317147624be8ea27e53b8cab72f9a..540dd471d259d7b7581de031fb06fb98296fe921 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -261,7 +261,7 @@ sync-gitlab-spack-instance:
     # There is a known spack bug (https://github.com/spack/spack/issues/29447) in installing test dependencies for installation tests. The workaround suggested
     # in the issue is to NOT concretize separately, but simply remove the .lock file and let the enironment be concretized by the spack install command:
     - rm $SPACK_ROOT/var/spack/environments/$SPACK_NFS_ENV/spack.lock || echo "No spack.lock file"
-    - spack install -y -j2 --fresh --no-check-signature --test root
+    - spack install -y -j2 --fresh --test root
     - spack module tcl refresh -y
     - spack reindex
     - spack env loads -r
diff --git a/install_spack_env.sh b/install_spack_env.sh
index 9ea0ac73211faebab0f29bdda0aca2e9c452fbcb..c5aaa511890310e7df2b1f8f615b4e9812643b76 100644
--- a/install_spack_env.sh
+++ b/install_spack_env.sh
@@ -54,7 +54,7 @@ spack env activate $EBRAINS_SPACK_ENV
 # remove the .lock file and let the enironment be concretized by the spack install command:
 rm $SPACK_ROOT/var/spack/environments/$EBRAINS_SPACK_ENV/spack.lock || echo "No spack.lock file"
 # install the environment, use 2 jobs to reduce the amount of required RAM
-spack install -y -j2 --fresh --no-check-signature --test root
+spack install -y -j2 --fresh --test root
 
 # rebuild spack's database
 spack reindex