diff --git a/install-nix.sh b/install-nix.sh
index 879e214..cbab5c3 100755
--- a/install-nix.sh
+++ b/install-nix.sh
@@ -56,7 +56,7 @@ if [[ -n "${INPUT_EXTRA_NIX_CONFIG:-}" ]]; then
   add_config "$INPUT_EXTRA_NIX_CONFIG"
 fi
 if [[ ! $INPUT_EXTRA_NIX_CONFIG =~ "experimental-features" ]]; then
-  add_config "experimental-features = nix-command flakes"
+  add_config "experimental-features = nix-command flakes auto-allocate-uids"
 fi
 # Always allow substituting from the cache, even if the derivation has `allowSubstitutes = false`.
 # This is a CI optimisation to avoid having to download the inputs for already-cached derivations to rebuild trivial text files.
@@ -74,8 +74,9 @@ installer_options=(
 if [[ (! $INPUT_INSTALL_OPTIONS =~ "--no-daemon") && ($OSTYPE =~ darwin || -e /run/systemd/system) ]]; then
   installer_options+=(
     --daemon
-    --daemon-user-count "$(python3 -c 'import multiprocessing as mp; print(mp.cpu_count() * 2)')"
+    --daemon-user-count 1
   )
+  add_config "auto-allocate-uids = true"
 else
   # "fix" the following error when running nix*
   # error: the group 'nixbld' specified in 'build-users-group' does not exist