diff --git a/buildPy2exe.py b/buildPy2exe.py
index d972554..84c357e 100755
--- a/buildPy2exe.py
+++ b/buildPy2exe.py
@@ -30,7 +30,7 @@ import syncplay
 from syncplay.messages import getMissingStrings
 
 missingStrings = getMissingStrings()
-if missingStrings is not None and missingStrings is not "":
+if missingStrings is not None and missingStrings != "":
     import warnings
     warnings.warn("MISSING/UNUSED STRINGS DETECTED:\n{}".format(missingStrings))
 
@@ -718,4 +718,4 @@ info = dict(
 )
 
 sys.argv.extend(['py2exe'])
-setup(**info)
\ No newline at end of file
+setup(**info)
diff --git a/syncplay/client.py b/syncplay/client.py
index 3f2c7a9..e6d7934 100755
--- a/syncplay/client.py
+++ b/syncplay/client.py
@@ -135,7 +135,7 @@ class SyncplayClient(object):
 
         if constants.DEBUG_MODE and constants.WARN_ABOUT_MISSING_STRINGS:
             missingStrings = getMissingStrings()
-            if missingStrings is not None and missingStrings is not "":
+            if missingStrings is not None and missingStrings != "":
                 self.ui.showDebugMessage("MISSING/UNUSED STRINGS DETECTED:\n{}".format(missingStrings))
 
     def initProtocol(self, protocol):
diff --git a/syncplay/ui/GuiConfiguration.py b/syncplay/ui/GuiConfiguration.py
index f062707..ee0f0a8 100755
--- a/syncplay/ui/GuiConfiguration.py
+++ b/syncplay/ui/GuiConfiguration.py
@@ -320,7 +320,7 @@ class ConfigDialog(QtWidgets.QDialog):
         try:
             self.lastCheckedForUpdates = settings.value("lastCheckedQt", None)
             if self.lastCheckedForUpdates:
-                if self.config["lastCheckedForUpdates"] is not None and self.config["lastCheckedForUpdates"] is not "":
+                if self.config["lastCheckedForUpdates"] is not None and self.config["lastCheckedForUpdates"] != "":
                     if self.lastCheckedForUpdates.toPython() > datetime.strptime(self.config["lastCheckedForUpdates"], "%Y-%m-%d %H:%M:%S.%f"):
                         self.config["lastCheckedForUpdates"] = self.lastCheckedForUpdates.toString("yyyy-MM-d HH:mm:ss.z")
                 else: