diff --git a/init/eessi_defaults b/init/eessi_defaults
index 3fdfa53976..da057fbfd2 100644
--- a/init/eessi_defaults
+++ b/init/eessi_defaults
@@ -11,5 +11,6 @@
 export EESSI_CVMFS_REPO="${EESSI_CVMFS_REPO_OVERRIDE:=/cvmfs/pilot.nessi.no}"
 export EESSI_VERSION="${EESSI_VERSION_OVERRIDE:=2023.06}"
 # use archdetect by default, unless otherwise specified
-export EESSI_USE_ARCHDETECT="${EESSI_USE_ARCHDETECT:=1}"
-export EESSI_USE_ARCHSPEC="${EESSI_USE_ARCHSPEC:=0}"
+# 2024-01-16: switch back to archspec with NESSI for now
+export EESSI_USE_ARCHDETECT="${EESSI_USE_ARCHDETECT:=0}"
+export EESSI_USE_ARCHSPEC="${EESSI_USE_ARCHSPEC:=1}"