diff --git a/devops-service/app/api2/handlers/project.rb b/devops-service/app/api2/handlers/project.rb
index aeb034e..570dab8 100644
--- a/devops-service/app/api2/handlers/project.rb
+++ b/devops-service/app/api2/handlers/project.rb
@@ -62,6 +62,8 @@ module Devops
           env = parser.add_or_update_deploy_env
           begin
             db_env = project.deploy_env(deploy_env)
+            servers = Devops::Db.connector.servers_by_project_and_deploy_env(id, deploy_env)
+            raise InvalidRecord.new("Can not update environment '#{deploy_env}', there are #{servers.size} servers on it") unless servers.empty?
             begin
               project.deploy_env(env.identifier)
               raise InvalidRecord.new("Can not change environment '#{deploy_env}' to '#{env.identifier}', environment '#{env.identifier}' already exist") unless deploy_env == env.identifier
diff --git a/devops-service/db/mongo/connectors/server.rb b/devops-service/db/mongo/connectors/server.rb
index b90a3a0..bfebcc2 100644
--- a/devops-service/db/mongo/connectors/server.rb
+++ b/devops-service/db/mongo/connectors/server.rb
@@ -41,6 +41,11 @@ module Connectors
       list(query)
     end
 
+    def servers_by_project_and_deploy_env project, env
+      query = {project: project, deploy_env: env}
+      list(query)
+    end
+
     def server_by_instance_id(id)
       find_server('_id' => id)
     end
diff --git a/devops-service/db/mongo/mongo_connector.rb b/devops-service/db/mongo/mongo_connector.rb
index 71e0bd1..714c927 100644
--- a/devops-service/db/mongo/mongo_connector.rb
+++ b/devops-service/db/mongo/mongo_connector.rb
@@ -26,7 +26,7 @@ class MongoConnector
     :project_template_delete] => :projects_templates_connector,
     [:servers_find, :servers, :stack_servers, :servers_by_names, :server_by_instance_id,
     :server_by_chef_node_name, :servers_by_key, :server_insert,
-    :server_delete, :server_update, :server_set_chef_node_name, :stack_servers_delete, :set_server_run_list] => :servers_connector,
+    :server_delete, :server_update, :server_set_chef_node_name, :stack_servers_delete, :set_server_run_list, :servers_by_project_and_deploy_env] => :servers_connector,
     [:user_auth, :user, :users, :users_names, :user_insert, :user_delete,
     :user_update, :create_root_user, :check_user_privileges] => :users_connector,
     [:keys, :key, :key_insert, :key_delete] => :keys_connector,