diff --git a/modoboa_installer/package.py b/modoboa_installer/package.py
index a7342073..8aa764fe 100644
--- a/modoboa_installer/package.py
+++ b/modoboa_installer/package.py
@@ -16,6 +16,12 @@ def preconfigure(self, name, question, qtype, answer):
         """Empty method."""
         pass
 
+    def prepare_system(self):
+        pass
+
+    def restore_system(self):
+        pass
+
 
 class DEBPackage(Package):
     """DEB based operations."""
@@ -25,6 +31,16 @@ class DEBPackage(Package):
     def __init__(self, dist_name):
         super(DEBPackage, self).__init__(dist_name)
         self.index_updated = False
+        self.policy_file = "/usr/sbin/policy-rc.d"
+
+    def prepare_system(self):
+        """Make sure services don't start at installation."""
+        with open(self.policy_file, "w") as fp:
+            fp.write("exit 101\n")
+        utils.exec_cmd("chmod +x {}".format(self.policy_file))
+
+    def restore_system(self):
+        utils.exec_cmd("rm -f {}".format(self.policy_file))
 
     def update(self):
         """Update local cache."""
diff --git a/run.py b/run.py
index 50ae6ddf..fa5b8ff4 100755
--- a/run.py
+++ b/run.py
@@ -112,6 +112,7 @@ def main(input_args):
         "The process can be long, feel free to take a coffee "
         "and come back later ;)", utils.BLUE)
     utils.printcolor("Starting...", utils.GREEN)
+    package.backend.prepare_system()
     package.backend.install_many(["sudo", "wget"])
     ssl_backend = ssl.get_backend(config)
     if ssl_backend and not args.upgrade:
@@ -126,6 +127,7 @@ def main(input_args):
     scripts.install("postfix", config, args.upgrade)
     scripts.install("dovecot", config, args.upgrade)
     system.restart_service("cron")
+    package.backend.restore_system()
     utils.printcolor(
         "Congratulations! You can enjoy Modoboa at https://{} (admin:password)"
         .format(config.get("general", "hostname")),