diff --git a/flake.nix b/flake.nix
index c538e47e8..6deb09f22 100644
--- a/flake.nix
+++ b/flake.nix
@@ -552,7 +552,7 @@
         # tarball for the user's system and calls the second half of the
         # installation script.
         installerScript = installScriptFor [ "x86_64-linux" "i686-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" "armv6l-linux" "armv7l-linux" ];
-        installerScriptForGHA = installScriptFor [ "x86_64-linux" "x86_64-darwin" "armv6l-linux" "armv7l-linux"];
+        installerScriptForGHA = installScriptFor [ "x86_64-linux" "aarch64-darwin" "armv6l-linux" "armv7l-linux"];
 
         # docker image with Nix inside
         dockerImage = lib.genAttrs linux64BitSystems (system: self.packages.${system}.dockerImage);
diff --git a/scripts/install-darwin-multi-user.sh b/scripts/install-darwin-multi-user.sh
index ec28d1a35..3b6c85568 100644
--- a/scripts/install-darwin-multi-user.sh
+++ b/scripts/install-darwin-multi-user.sh
@@ -3,8 +3,6 @@
 set -eu
 set -o pipefail
 
-<<<<<<< HEAD
-=======
 # System specific settings
 # Notes:
 # - up to macOS Big Sur we used the same GID/UIDs as Linux (30000:30001-32)
@@ -19,12 +17,9 @@ export NIX_FIRST_BUILD_UID="${NIX_FIRST_BUILD_UID:-351}"
 export NIX_BUILD_GROUP_ID="${NIX_BUILD_GROUP_ID:-350}"
 export NIX_BUILD_USER_NAME_TEMPLATE="_nixbld%d"
 
->>>>>>> df36ff0d1 (install-darwin: fix _nixbld uids for macOS sequoia)
 readonly NIX_DAEMON_DEST=/Library/LaunchDaemons/org.nixos.nix-daemon.plist
 # create by default; set 0 to DIY, use a symlink, etc.
 readonly NIX_VOLUME_CREATE=${NIX_VOLUME_CREATE:-1} # now default
-NIX_FIRST_BUILD_UID="301"
-NIX_BUILD_USER_NAME_TEMPLATE="_nixbld%d"
 
 # caution: may update times on / if not run as normal non-root user
 read_only_root() {
diff --git a/scripts/install-multi-user.sh b/scripts/install-multi-user.sh
index e0313ab26..79f886b0c 100644
--- a/scripts/install-multi-user.sh
+++ b/scripts/install-multi-user.sh
@@ -24,16 +24,10 @@ readonly RED='\033[31m'
 # as creating each user takes non-trivial amount of time on macos
 readonly NIX_USER_COUNT=${NIX_USER_COUNT:-32}
 readonly NIX_BUILD_GROUP_NAME="nixbld"
-<<<<<<< HEAD
-# darwin installer needs to override these
-NIX_FIRST_BUILD_UID="${NIX_FIRST_BUILD_UID:-30001}"
-NIX_BUILD_USER_NAME_TEMPLATE="nixbld%d"
-=======
 # each system specific installer must set these:
 #   NIX_FIRST_BUILD_UID
 #   NIX_BUILD_GROUP_ID
 #   NIX_BUILD_USER_NAME_TEMPLATE
->>>>>>> 75567423f (install-darwin: move nixbld gid to match first UID)
 # Please don't change this. We don't support it, because the
 # default shell profile that comes with Nix doesn't support it.
 readonly NIX_ROOT="/nix"
@@ -711,6 +705,12 @@ EOF
     fi
 }
 
+check_required_system_specific_settings() {
+    if [ -z "${NIX_FIRST_BUILD_UID+x}" ] || [ -z "${NIX_BUILD_USER_NAME_TEMPLATE+x}" ]; then
+        failure "Internal error: System specific installer for $(uname) ($1) does not export required settings."
+    fi
+}
+
 welcome_to_nix() {
     local -r NIX_UID_RANGES="${NIX_FIRST_BUILD_UID}..$((NIX_FIRST_BUILD_UID + NIX_USER_COUNT - 1))"
     local -r RANGE_TEXT=$(echo -ne "${BLUE}(uids [${NIX_UID_RANGES}])${ESC}")
@@ -730,7 +730,9 @@ manager. This will happen in a few stages:
    if you are ready to continue.
 
 3. Create the system users ${RANGE_TEXT} and groups ${GROUP_TEXT}
-   that the Nix daemon uses to run builds.
+   that the Nix daemon uses to run builds. To create system users
+   in a different range, exit and run this tool again with
+   NIX_FIRST_BUILD_UID set.
 
 4. Perform the basic installation of the Nix files daemon.
 
@@ -972,13 +974,16 @@ main() {
     if is_os_darwin; then
         # shellcheck source=./install-darwin-multi-user.sh
         . "$EXTRACTED_NIX_PATH/install-darwin-multi-user.sh"
+        check_required_system_specific_settings "install-darwin-multi-user.sh"
     elif is_os_linux; then
         # shellcheck source=./install-systemd-multi-user.sh
         . "$EXTRACTED_NIX_PATH/install-systemd-multi-user.sh" # most of this works on non-systemd distros also
+        check_required_system_specific_settings "install-systemd-multi-user.sh"
     else
         failure "Sorry, I don't know what to do on $(uname)"
     fi
 
+
     welcome_to_nix
 
     if ! is_root; then
diff --git a/scripts/install-systemd-multi-user.sh b/scripts/install-systemd-multi-user.sh
index a5857e689..fd8cdab0b 100755
--- a/scripts/install-systemd-multi-user.sh
+++ b/scripts/install-systemd-multi-user.sh
@@ -3,14 +3,11 @@
 set -eu
 set -o pipefail
 
-<<<<<<< HEAD
-=======
 # System specific settings
 export NIX_FIRST_BUILD_UID="${NIX_FIRST_BUILD_UID:-30001}"
 export NIX_BUILD_GROUP_ID="${NIX_BUILD_GROUP_ID:-30000}"
 export NIX_BUILD_USER_NAME_TEMPLATE="nixbld%d"
 
->>>>>>> 75567423f (install-darwin: move nixbld gid to match first UID)
 readonly SERVICE_SRC=/lib/systemd/system/nix-daemon.service
 readonly SERVICE_DEST=/etc/systemd/system/nix-daemon.service