diff --git a/.update.sh b/.update.sh
index 1f13374..47c09fa 100644
--- a/.update.sh
+++ b/.update.sh
@@ -3,12 +3,13 @@
 THIS_DIR=$( cd "$( dirname "${BASH_SOURCE[0]:-${(%):-%x}}" )" && pwd )
 THIS_FILE=$(basename "${BASH_SOURCE}")
 source "$THIS_DIR/tools/common.sh"
+DFS_ENABLE_RET=${DFS_ENABLE_RET:-0}
 
 # get the specified commit id
-dfs_commit=$(curl -fsSL https://api.beardic.cn/get-var/dfs-commit-id)
-if [[ ${#dfs_commit} != 40 ]]; then
+DFS_COMMIT=$(curl -fsSL https://api.beardic.cn/get-var/dfs-commit-id)
+if [[ ${#DFS_COMMIT} != 40 ]]; then
     fmt_error "invalid commit id"
-    post_log "ERROR" "$THIS_FILE" "invalid commit id: ${dfs_commit}"
+    post_log "ERROR" "$THIS_FILE" "invalid commit id: ${DFS_COMMIT}"
     exit
 fi
 # fetch origin
@@ -20,16 +21,16 @@ if [[ -n "$(git status -s)" ]]; then
     exit
 fi
 # update
-if [[ "$(git rev-parse HEAD)" == "$dfs_commit" ]]; then
+if [[ "$(git rev-parse HEAD)" == "$DFS_COMMIT" ]]; then
     fmt_info "nothing to do"
     post_log "INFO" "$THIS_FILE" "nothing to do"
 else
-    fmt_info "checking out to commit $dfs_commit ..."
+    fmt_info "checking out to commit $DFS_COMMIT ..."
     if [[ -z "$DFS_DEV" ]]; then
-        git -c advice.detachedHead=false checkout $dfs_commit
+        post_log "INFO" "$THIS_FILE" "will check out to commit $DFS_COMMIT"
+        git -c advice.detachedHead=false checkout $DFS_COMMIT
+        cp ./.update.sh ./update.sh && chmod +x ./update.sh && exit $DFS_ENABLE_RET
     else
         fmt_warning "won't really checkout in dev mode"
     fi
-    post_log "INFO" "$THIS_FILE" "will check out to commit $dfs_commit"
-    cp ./.update.sh ./update.sh && chmod +x ./update.sh && exit
 fi
diff --git a/install.sh b/install.sh
index 2b61496..f7e7ad5 100755
--- a/install.sh
+++ b/install.sh
@@ -219,7 +219,11 @@ install_update(){
     cp "${DOTFILES}/.update.sh" "${DOTFILES}/update.sh"
     chmod +x "${DOTFILES}/update.sh"
     fmt_note "running update.sh ..."
-    ${DOTFILES}/update.sh
+    DFS_ENABLE_RET=1 ${DOTFILES}/update.sh
+    if [[ $? == 1 ]]; then
+        fmt_note "dfs updated. re-running install.sh ..."
+        "${DOTFILES}/install.sh" && exit
+    fi
 }
 
 uninstall_update(){
@@ -228,8 +232,8 @@ uninstall_update(){
 }
 
 install(){
-    preinstall_check
     install_update
+    preinstall_check
     install_crontab
     install_file_content
     install_symlink