diff --git a/system_setup/install.sh b/system_setup/install.sh
index 67dcab5..e02618f 100755
--- a/system_setup/install.sh
+++ b/system_setup/install.sh
@@ -69,7 +69,7 @@ do_clone_and_done() {
     info "Cloning $REPO_URL into $MOUNT_POINT..."
     cd "$MOUNT_POINT" || die "Cannot cd to $MOUNT_POINT."
     git clone --progress --depth 1 -b $REPO_BRANCH "$REPO_URL" . || die "git clone failed."
-    source "$(dirname "$0")/setup_system.inc.sh"
+    ${MOUNT_POINT}/setup_system.inc.sh
     finish_install "$dev"
 }
 
@@ -361,10 +361,8 @@ if [[ -n "$EXISTING_OEMDRV_DEV" ]]; then
         fi
 
         if [[ -f "$MOUNT_POINT/system_setup/setup_system.inc.sh" && -f "$MOUNT_POINT/config/setup_system.conf" ]]; then
-            info "Sourcing existing setup_system.inc.sh..."
-            pushd "$MOUNT_POINT/system_setup" > /dev/null
-            source setup_system.inc.sh
-            popd > /dev/null
+            info "Reading existing configuration..."
+            $MOUNT_POINT/system_setup/setup_system.inc.sh
         fi
 
         # ── Check existing git repository origin ──────────────────────────────
@@ -393,7 +391,7 @@ if [[ -n "$EXISTING_OEMDRV_DEV" ]]; then
                             || die "git fetch failed."
                         git -C "$MOUNT_POINT" checkout -B "$REPO_BRANCH" FETCH_HEAD \
                             || die "git checkout failed."
-                        source "$MOUNT_POINT/system_setup/setup_system.inc.sh"
+                        $MOUNT_POINT/system_setup/setup_system.inc.sh
                         finish_install "$EXISTING_OEMDRV_DEV"
                         exit 0
                         ;;
@@ -405,7 +403,7 @@ if [[ -n "$EXISTING_OEMDRV_DEV" ]]; then
                             || die "git fetch failed."
                         git -C "$MOUNT_POINT" checkout -B "$REPO_BRANCH" FETCH_HEAD \
                             || die "git checkout failed."
-                        source "$MOUNT_POINT/system_setup/setup_system.inc.sh"
+                        $MOUNT_POINT/system_setup/setup_system.inc.sh
                         finish_install "$EXISTING_OEMDRV_DEV"
                         exit 0
                         ;;