diff --git a/lib/cijoe/server.rb b/lib/cijoe/server.rb
index 01ebafe..684f54b 100644
--- a/lib/cijoe/server.rb
+++ b/lib/cijoe/server.rb
@@ -39,7 +39,10 @@ def self.start(host, port, project_path)
       end
 
       post '/' do
-        joe.build if params[:payload].to_s.include? joe.git_branch
+        payload = params[:payload].to_s
+        if payload.empty? || payload.include?(joe.git_branch)
+          joe.build
+        end
         redirect '/'
       end