diff --git a/addons/report/controllers/main.py b/addons/report/controllers/main.py
index 99a672a1dd8..ecdf5b09647 100644
--- a/addons/report/controllers/main.py
+++ b/addons/report/controllers/main.py
@@ -23,6 +23,7 @@ from openerp.osv.osv import except_osv
 from openerp.addons.web import http
 from openerp.tools.translate import _
 from openerp.addons.web.http import request
+import openerp.tools.config as config
 
 import time
 import base64
@@ -35,6 +36,10 @@ try:
     import cStringIO as StringIO
 except ImportError:
     import StringIO
+import psutil
+import signal
+import os
+
 
 from pyPdf import PdfFileWriter, PdfFileReader
 from werkzeug import exceptions
@@ -322,6 +327,12 @@ class Report(http.Controller):
             content_file.seek(0)
 
             try:
+                # If the server is running with only one worker, increase it to two to be able
+                # to serve the http request from wkhtmltopdf.
+                if config['workers'] == 1:
+                    ppid = psutil.Process(os.getpid()).ppid
+                    os.kill(ppid, signal.SIGTTIN)
+
                 wkhtmltopdf = command + command_args + command_arg_local
                 wkhtmltopdf += [content_file.name] + [pdfreport.name]
 
@@ -329,6 +340,9 @@ class Report(http.Controller):
                                            stderr=subprocess.PIPE)
                 out, err = process.communicate()
 
+                if config['workers'] == 1:
+                    os.kill(ppid, signal.SIGTTOU)
+
                 if process.returncode != 0:
                     raise except_osv(_('Report (PDF)'),
                                      _('wkhtmltopdf-0.12 failed with error code = %s. '