diff --git a/mom/Collectors/Collector.py b/mom/Collectors/Collector.py
index ae8fbcc..dfd3bed 100644
--- a/mom/Collectors/Collector.py
+++ b/mom/Collectors/Collector.py
@@ -92,7 +92,7 @@ def get_collectors(config_str, properties, global_config):
             module = __import__('mom.Collectors.' + name, None, None, name)
             collectors.append(getattr(module, name)(properties))
         except ImportError:
-            logger.warn("Unable to import collector: %s", name)
+            logger.warning("Unable to import collector: %s", name)
             return None
         except FatalError as e:
             logger.error("Fatal Collector error: %s", e.msg)
diff --git a/mom/Collectors/GuestMemory.py b/mom/Collectors/GuestMemory.py
index 3eda53c..0e06075 100644
--- a/mom/Collectors/GuestMemory.py
+++ b/mom/Collectors/GuestMemory.py
@@ -42,7 +42,7 @@ def stats_error(self, msg):
         problem.  Otherwise the log will be overrun with noise.
         """
         if self.memstats_available:
-            self.logger.warn(msg)
+            self.logger.warning(msg)
         self.memstats_available = False
 
     def collect(self):
diff --git a/mom/Collectors/GuestNetworkDaemon.py b/mom/Collectors/GuestNetworkDaemon.py
index 89a82ae..685fb87 100755
--- a/mom/Collectors/GuestNetworkDaemon.py
+++ b/mom/Collectors/GuestNetworkDaemon.py
@@ -95,13 +95,13 @@ def get_guest_ip(self, properties):
         try:
             output = Popen([prog, name], stdout=PIPE).communicate()[0].decode("utf-8")
         except OSError as e:
-            self.logger.warn("Cannot call name-to-ip-helper: %s", e.strerror)
+            self.logger.warning("Cannot call name-to-ip-helper: %s", e.strerror)
             return None
         matches = re.findall(r"^(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})",
                              output, re.M)
         if len(matches) != 1:
-            self.logger.warn("Output from name-to-ip-helper %s is not an IP " \
-                             "address. (output = '%s')", name, output)
+            self.logger.warning("Output from name-to-ip-helper %s is not an IP " \
+                                "address. (output = '%s')", name, output)
             return None
         else:
             ip = matches[0]
@@ -217,7 +217,7 @@ def session(self, conn, addr):
                 else:
                     break
             except socket.error as msg:
-                self.logger.warn("Exception: %s" % msg)
+                self.logger.warning("Exception: %s" % msg)
                 break
         sock_close(conn)
         self.logger.debug("Connection closed")
diff --git a/mom/Collectors/GuestQemuAgent.py b/mom/Collectors/GuestQemuAgent.py
index bd548b8..2c39275 100644
--- a/mom/Collectors/GuestQemuAgent.py
+++ b/mom/Collectors/GuestQemuAgent.py
@@ -49,9 +49,9 @@ def __init__(self, properties):
             socket_name = socket_name_template % {'name' : self.name}
         except KeyError as e:
             socket_name = self.name + '.agent'
-            self.logger.warn("Error substituting socket name " \
-                              "template. Invalid key: %s" % e)
-            self.logger.warn("Using socket name %s." % socket_name)
+            self.logger.warning("Error substituting socket name " \
+                                "template. Invalid key: %s" % e)
+            self.logger.warning("Using socket name %s." % socket_name)
 
         self.sockets = [ None, "%s/%s" % (socket_path, socket_name) ]
         self.agent = None
diff --git a/mom/Controllers/KSM.py b/mom/Controllers/KSM.py
index 59cbf10..4be56b7 100644
--- a/mom/Controllers/KSM.py
+++ b/mom/Controllers/KSM.py
@@ -38,7 +38,7 @@ def write_value(self, fname, value):
             with open(fname, 'w') as f:
                 f.write(str(value))
         except IOError as e:
-            self.logger.warn("KSM: Failed to write %s: %s", fname, e.strerror)
+            self.logger.warning("KSM: Failed to write %s: %s", fname, e.strerror)
 
     def process(self, host, guests):
         outputs = {}
diff --git a/mom/HypervisorInterfaces/libvirtInterface.py b/mom/HypervisorInterfaces/libvirtInterface.py
index 64610b3..a856303 100644
--- a/mom/HypervisorInterfaces/libvirtInterface.py
+++ b/mom/HypervisorInterfaces/libvirtInterface.py
@@ -127,12 +127,12 @@ def _domainGetPid(self, uuid):
         p1 = Popen(["ps", "axww"], stdout=PIPE).communicate()[0].decode("utf-8")
         matches = re.findall(r"^\s*(\d+)\s+.*" + uuid, p1, re.M)
         if len(matches) < 1:
-            self.logger.warn("No matching process for domain with uuid %s", \
-                             uuid)
+            self.logger.warning("No matching process for domain with uuid %s", \
+                                uuid)
             return None
         elif len(matches) > 1:
-            self.logger.warn("Too many process matches for domain with uuid %s",\
-                             uuid)
+            self.logger.warning("Too many process matches for domain with uuid %s",\
+                                uuid)
             return None
         return int(matches[0])
 
@@ -158,13 +158,13 @@ def _handleException(self, e):
         do_nothing_errors = (libvirt.VIR_ERR_NO_DOMAIN,)
         error = e.get_error_code()
         if error in reconnect_errors:
-            self.logger.warn('libvirtInterface: connection lost, reconnecting.')
+            self.logger.warning('libvirtInterface: connection lost, reconnecting.')
             self._reconnect()
         elif error in do_nothing_errors:
             pass
         else:
-            self.logger.warn('libvirtInterface: Unhandled libvirt exception '\
-                             '(%i).', error)
+            self.logger.warning('libvirtInterface: Unhandled libvirt exception '\
+                                '(%i).', error)
 
     def _domainSetBalloonTarget(self, domain, target):
         try:
@@ -292,7 +292,7 @@ def setVmBalloonTarget(self, uuid, target):
         if dom is not None:
             if self._domainSetBalloonTarget(dom, target):
                 name = self._domainGetName(dom)
-                self.logger.warn("Error while ballooning guest:%i", name)
+                self.logger.warning("Error while ballooning guest:%i", name)
 
     def setVmCpuTune(self, uuid, quota, period):
         dom = self._getDomainFromUUID(uuid)
@@ -308,7 +308,7 @@ def write_value(fname, value):
                 with open(fname, 'w') as f:
                     f.write(str(value))
             except IOError as e:
-                self.logger.warn("KSM: Failed to write %s: %s", fname, e.strerror)
+                self.logger.warning("KSM: Failed to write %s: %s", fname, e.strerror)
 
         for (key, val) in tuningParams.items():
             write_value('/sys/kernel/mm/ksm/%s' % key, val)
diff --git a/mom/HypervisorInterfaces/vdsmjsonrpcclientInterface.py b/mom/HypervisorInterfaces/vdsmjsonrpcclientInterface.py
index d6b9e66..b47c0e1 100644
--- a/mom/HypervisorInterfaces/vdsmjsonrpcclientInterface.py
+++ b/mom/HypervisorInterfaces/vdsmjsonrpcclientInterface.py
@@ -35,7 +35,7 @@ def __init__(self):
         try:
             use_tls = vdsmconfig.getboolean('vars', 'ssl')
         except Exception as e:
-            self._logger.warn("Failed to read VDSM config file, using SSL connection. %s", e)
+            self._logger.warning("Failed to read VDSM config file, using SSL connection. %s", e)
             use_tls = True
 
         try:
diff --git a/mom/Monitor.py b/mom/Monitor.py
index 978bc3d..aaa1053 100644
--- a/mom/Monitor.py
+++ b/mom/Monitor.py
@@ -178,7 +178,7 @@ def _disp_collection_error(self, message=None):
             if self.ready is False:
                 self.logger.debug('%s: %s', self.name, message)
             else: # True or None
-                self.logger.warn('%s: %s', self.name, message)
+                self.logger.warning('%s: %s', self.name, message)
 
     def _set_not_ready(self, message=None):
         self.ready = False
diff --git a/mom/Plotter.py b/mom/Plotter.py
index c0228e3..9589e32 100644
--- a/mom/Plotter.py
+++ b/mom/Plotter.py
@@ -27,7 +27,7 @@ def __init__(self, plot_dir, name):
             self.file = open(filename, 'a')
         except IOError as e:
             logger = logging.getLogger('mom.Plotter')
-            logger.warn("Cannot open plot file %s: %s" , filename, e.strerror)
+            logger.warning("Cannot open plot file %s: %s" , filename, e.strerror)
 
     def __del__(self):
         if self.file is not None:
diff --git a/mom/Policy/Policy.py b/mom/Policy/Policy.py
index c1bd71d..63d353f 100644
--- a/mom/Policy/Policy.py
+++ b/mom/Policy/Policy.py
@@ -63,7 +63,7 @@ def set_policy(self, name, policyStr):
             try:
                 self.code = get_code(Evaluator(), self._cat_policies())
             except PolicyError as e:
-                self.logger.warn("Unable to load policy: %s" % e)
+                self.logger.warning("Unable to load policy: %s" % e)
                 if oldStr is None:
                     del self.policy_strings[name]
                 else:
diff --git a/mom/PolicyEngine.py b/mom/PolicyEngine.py
index a608195..fbd4146 100644
--- a/mom/PolicyEngine.py
+++ b/mom/PolicyEngine.py
@@ -48,7 +48,7 @@ def read_policy(file_name, policy_name):
                 with open(file_name, 'r') as f:
                     policyStr = f.read()
             except IOError as e:
-                self.logger.warn("Unable to read policy file: %s" % e)
+                self.logger.warning("Unable to read policy file: %s" % e)
                 return False
             return self.policy.set_policy(policy_name, policyStr)
 
@@ -61,7 +61,7 @@ def read_policy(file_name, policy_name):
             try:
                 names = sorted(os.listdir(policy_dir))
             except OSError as e:
-                self.logger.warn("Unable to read directory '%s': %s" % (
+                self.logger.warning("Unable to read directory '%s': %s" % (
                                     policy_dir, e.strerror))
                 return False
             for name in names:
@@ -110,7 +110,7 @@ def get_controllers(self):
                 module = __import__('mom.Controllers.' + name, None, None, name)
                 self.logger.debug("Loaded %s controller", name)
             except ImportError:
-                self.logger.warn("Unable to import controller: %s", name)
+                self.logger.warning("Unable to import controller: %s", name)
                 continue
             self.controllers.append(getattr(module, name)(self.properties))
 
diff --git a/mom/__init__.py b/mom/__init__.py
index e6dc27b..3e4b576 100644
--- a/mom/__init__.py
+++ b/mom/__init__.py
@@ -186,7 +186,7 @@ def _get_plot_subdir(self, basedir):
         try:
             names = os.listdir(basedir)
         except OSError as e:
-            self.logger.warn("Cannot read plot-basedir %s: %s", basedir, e.strerror)
+            self.logger.warning("Cannot read plot-basedir %s: %s", basedir, e.strerror)
             return ''
         seq_num = -1
         for name in names:
@@ -198,13 +198,13 @@ def _get_plot_subdir(self, basedir):
         seq_num = seq_num + 1
         dir = "%s/momplot-%03d" % (basedir, seq_num)
         if seq_num > 999:
-            self.logger.warn("Cannot create plot-dir because the sequence number "\
+            self.logger.warning("Cannot create plot-dir because the sequence number "\
                   "is out of range.  Clear the directory or choose a different one")
             return ''
         try:
             os.mkdir(dir)
         except OSError as e:
-            self.logger.warn("Cannot create plot-dir %s: %s", dir, e.strerror)
+            self.logger.warning("Cannot create plot-dir %s: %s", dir, e.strerror)
             return ''
         return dir