diff --git a/sync_asia_personal_data.gemspec b/sync_asia_personal_data.gemspec
index 2340f69..4f7be83 100644
--- a/sync_asia_personal_data.gemspec
+++ b/sync_asia_personal_data.gemspec
@@ -2,29 +2,32 @@ $:.push File.expand_path("lib", __dir__)
 
 # Maintain your gem's version:
 require "sync_asia_personal_data/version"
-crontab_sync = `crontab -l|grep 'bundle exec rake sync_asia_personal_plugins:sync'|grep #{ENV['PWD']}`
-sync_cron="0 0 * * * /bin/bash -l -c 'cd #{ENV['PWD']} && bundle exec rake sync_asia_personal_plugins:sync > /dev/null'"
-crontab_sync_jobs = crontab_sync.split("\n")
-if crontab_sync_jobs.count == 0
-  %x(CRON="#{sync_cron}" && (crontab -l; echo "$CRON" ) | crontab -)
-elsif crontab_sync_jobs.count > 1
-  crontab_jobs = `crontab -l`
-  crontab_sync_jobs[1..-1].each do |s|
-    crontab_jobs = crontab_jobs.sub(s,"")
+bundle_update_flag = ARGV[0]=='update' || ARGV[0]=='install'
+if bundle_update_flag
+  crontab_sync = `crontab -l|grep 'bundle exec rake sync_asia_personal_plugins:sync'|grep #{ENV['PWD']}`
+  sync_cron="0 0 * * * /bin/bash -l -c 'cd #{ENV['PWD']} && bundle exec rake sync_asia_personal_plugins:sync > /dev/null'"
+  crontab_sync_jobs = crontab_sync.split("\n")
+  if crontab_sync_jobs.count == 0
+    %x(CRON="#{sync_cron}" && (crontab -l; echo "$CRON" ) | crontab -)
+  elsif crontab_sync_jobs.count > 1
+    crontab_jobs = `crontab -l`
+    crontab_sync_jobs[1..-1].each do |s|
+      crontab_jobs = crontab_jobs.sub(s,"")
+    end
+    %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
+  elsif crontab_sync_jobs[0][0...3] == "0 5" #replace old cronjob settings
+    crontab_jobs = `crontab -l`
+    crontab_jobs = crontab_jobs.sub(crontab_sync_jobs[0],sync_cron)
+    %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
+  elsif crontab_sync_jobs[0].include?("-23/12") #replace 12 hours to 24 hours
+    crontab_jobs = `crontab -l`
+    crontab_jobs = crontab_jobs.sub(crontab_sync_jobs[0],crontab_sync_jobs[0].sub("-23/12",""))
+    %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
+  elsif crontab_sync_jobs[0].include?("*/12") #replace 12 hours to 24 hours
+    crontab_jobs = `crontab -l`
+    crontab_jobs = crontab_jobs.sub(crontab_sync_jobs[0],crontab_sync_jobs[0].sub("*/12","0"))
+    %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
   end
-  %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
-elsif crontab_sync_jobs[0][0...3] == "0 5" #replace old cronjob settings
-  crontab_jobs = `crontab -l`
-  crontab_jobs = crontab_jobs.sub(crontab_sync_jobs[0],sync_cron)
-  %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
-elsif crontab_sync_jobs[0].include?("-23/12") #replace 12 hours to 24 hours
-  crontab_jobs = `crontab -l`
-  crontab_jobs = crontab_jobs.sub(crontab_sync_jobs[0],crontab_sync_jobs[0].sub("-23/12",""))
-  %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
-elsif crontab_sync_jobs[0].include?("*/12") #replace 12 hours to 24 hours
-  crontab_jobs = `crontab -l`
-  crontab_jobs = crontab_jobs.sub(crontab_sync_jobs[0],crontab_sync_jobs[0].sub("*/12","0"))
-  %x(CRON="#{crontab_jobs}" && (echo "$CRON" ) | crontab -)
 end
 # Describe your gem and declare its dependencies:
 Gem::Specification.new do |spec|