diff --git a/NEWS b/NEWS
index 61992fad..48241fbe 100644
--- a/NEWS
+++ b/NEWS
@@ -70,6 +70,7 @@ Backward-incompatible changes:
     * Support for psutil < 5.3.0 has been dropped
     * Minimum supported Docker API version is now 1.21 (Docker plugins)
     * Support for InfluxDB < 0.9 is deprecated (InfluxDB exporter)
+    * Zeroconf lib should be pinned to 0.19.1 for Python 2.x 
     * --disable-<plugin> no longer available (use --disable-plugin <plugin>)
     * --export-<exporter> no longer available (use --export <exporter>)
 
diff --git a/optional-requirements.txt b/optional-requirements.txt
index 022423ff..a3abd92d 100644
--- a/optional-requirements.txt
+++ b/optional-requirements.txt
@@ -21,4 +21,5 @@ requests
 scandir; python_version < "3.5"
 statsd
 wifi
-zeroconf
+zeroconf==0.19.1; python_version < "3.0"
+zeroconf; python_version >= "3.0"
diff --git a/unitest-restful.py b/unitest-restful.py
index de5f4dcf..e6a58bec 100755
--- a/unitest-restful.py
+++ b/unitest-restful.py
@@ -32,7 +32,8 @@ from glances.compat import text_type
 import requests
 
 SERVER_PORT = 61234
-URL = "http://localhost:%s/api/2" % SERVER_PORT
+API_VERSION = 2
+URL = "http://localhost:{}/api/{}".format(SERVER_PORT, API_VERSION)
 pid = None
 
 # Unitest class