Index: manuskript-0.11.0/manuskript/exporter/pandoc/abstractPlainText.py
===================================================================
--- manuskript-0.11.0.orig/manuskript/exporter/pandoc/abstractPlainText.py
+++ manuskript-0.11.0/manuskript/exporter/pandoc/abstractPlainText.py
@@ -75,7 +75,7 @@ class pandocSetting:
         """Return whether the specific setting is active with the given format."""
 
         # Empty formats means all
-        if self.formats is "":
+        if self.formats != "":
             return True
 
         # "html" in "html markdown latex"
Index: manuskript-0.11.0/manuskript/importer/opmlImporter.py
===================================================================
--- manuskript-0.11.0.orig/manuskript/importer/opmlImporter.py
+++ manuskript-0.11.0/manuskript/importer/opmlImporter.py
@@ -121,4 +121,4 @@ class opmlImporter(abstractImporter):
         s = cls.restoreNewLines(inString)
         s = ''.join(s.split())
 
-        return len(s) is 0
+        return len(s) == 0
Index: manuskript-0.11.0/manuskript/main.py
===================================================================
--- manuskript-0.11.0.orig/manuskript/main.py
+++ manuskript-0.11.0/manuskript/main.py
@@ -101,7 +101,7 @@ def prepare(tests=False):
 
     def respectSystemDarkThemeSetting():
         """Adjusts the Qt theme to match the OS 'dark theme' setting configured by the user."""
-        if platform.system() is not 'Windows':
+        if platform.system() != 'Windows':
             return
 
         # Basic Windows 10 Dark Theme support.