diff --git a/docker/docker-py3-kms-minimal/Dockerfile b/docker/docker-py3-kms-minimal/Dockerfile
index 0080f379..e34ebf79 100644
--- a/docker/docker-py3-kms-minimal/Dockerfile
+++ b/docker/docker-py3-kms-minimal/Dockerfile
@@ -2,7 +2,7 @@
 
 FROM alpine:3.8
 
-ENV IP		0.0.0.0
+ENV IP		::
 ENV PORT		1688
 ENV EPID		""
 ENV LCID		1033
diff --git a/docker/docker-py3-kms/Dockerfile b/docker/docker-py3-kms/Dockerfile
index 607460e7..138003f6 100644
--- a/docker/docker-py3-kms/Dockerfile
+++ b/docker/docker-py3-kms/Dockerfile
@@ -9,8 +9,8 @@ FROM alpine:3.8
 
 # EN: IP-address
 # RU: IP-адрес
-ENV IP		0.0.0.0
-# The IP address to listen on. The default is "0.0.0.0" (all interfaces).
+ENV IP		::
+# The IP address to listen on. The default is "::" (all interfaces).
 
 # EN: TCP-port
 # RU: TCP-порт
@@ -115,4 +115,4 @@ WORKDIR /home/py-kms
 EXPOSE ${PORT}/tcp
 
 # Entry point
-ENTRYPOINT ["/usr/bin/start.sh"]
\ No newline at end of file
+ENTRYPOINT ["/usr/bin/start.sh"]
diff --git a/py-kms/pykms_Server.py b/py-kms/pykms_Server.py
index af99091d..694bdbd5 100755
--- a/py-kms/pykms_Server.py
+++ b/py-kms/pykms_Server.py
@@ -36,6 +36,7 @@ class KeyServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
         allow_reuse_address = True
 
         def __init__(self, server_address, RequestHandlerClass):
+                self.address_family = socket.AF_INET6 # This call make sure the server creates an IPv6 socket and NOT an IPv4 by default
                 socketserver.TCPServer.__init__(self, server_address, RequestHandlerClass)
                 self.__shutdown_request = False
                 self.r_service, self.w_service = os.pipe()