diff --git a/plinth/modules/backups/forms.py b/plinth/modules/backups/forms.py
index 32f4bc23e..08e813097 100644
--- a/plinth/modules/backups/forms.py
+++ b/plinth/modules/backups/forms.py
@@ -47,7 +47,7 @@ def _get_repository_choices():
 
 
 class CreateArchiveForm(forms.Form):
-    repository = forms.ChoiceField()
+    repository = forms.ChoiceField(label=_('Repository'))
     name = forms.RegexField(
         label=_('Name'),
         help_text=_('(Optional) Set a name for this backup archive'),
@@ -119,7 +119,7 @@ class EncryptedBackupsMixin(forms.Form):
         label=_('Encryption'), help_text=format_lazy(
             _('"Key in Repository" means that a '
               'password-protected key is stored with the backup.')),
-        choices=[('repokey', 'Key in Repository'), ('none', 'None')])
+        choices=[('repokey', _('Key in Repository')), ('none', _('None'))])
     encryption_passphrase = forms.CharField(
         label=_('Passphrase'),
         help_text=_('Passphrase; Only needed when using encryption.'),
diff --git a/plinth/modules/config/forms.py b/plinth/modules/config/forms.py
index 70f4dfed1..2194a0a7f 100644
--- a/plinth/modules/config/forms.py
+++ b/plinth/modules/config/forms.py
@@ -88,6 +88,7 @@ class ConfigurationForm(forms.Form):
         choices=get_homepage_choices)
 
     advanced_mode = forms.BooleanField(
-        label=_('Show advanced apps and features'), required=False,
-        help_text=_('Show apps and features that require more technical '
-                    'knowledge.'))
+        label=ugettext_lazy('Show advanced apps and features'), required=False,
+        help_text=ugettext_lazy(
+            'Show apps and features that require more technical '
+            'knowledge.'))
diff --git a/plinth/modules/diagnostics/__init__.py b/plinth/modules/diagnostics/__init__.py
index 80e4aec18..1984338dd 100644
--- a/plinth/modules/diagnostics/__init__.py
+++ b/plinth/modules/diagnostics/__init__.py
@@ -9,6 +9,7 @@ import logging
 import threading
 
 from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import ugettext_noop
 
 from plinth import app as app_module
 from plinth import daemon, menu
@@ -96,6 +97,12 @@ def run_on_all_enabled_modules():
         'progress_percentage': 0
     }
 
+    # Three result strings returned by tests, mark for translation and
+    # translate later.
+    ugettext_noop('passed')
+    ugettext_noop('failed')
+    ugettext_noop('error')
+
     apps = []
     for app in app_module.App.list():
         # XXX: Implement more cleanly.
diff --git a/plinth/modules/diagnostics/templates/diagnostics_results.html b/plinth/modules/diagnostics/templates/diagnostics_results.html
index 3dae9fe44..04c684b93 100644
--- a/plinth/modules/diagnostics/templates/diagnostics_results.html
+++ b/plinth/modules/diagnostics/templates/diagnostics_results.html
@@ -17,11 +17,11 @@
         <td>{{ test }}</td>
         <td>
           {% if result == 'passed' %}
-            <span class="label label-success">{{ result }}</span>
+            <span class="label label-success">{% trans result %}</span>
           {% elif result == 'failed' %}
-            <span class="label label-danger">{{ result }}</span>
+            <span class="label label-danger">{% trans result %}</span>
           {% elif result == 'error' %}
-            <span class="label label-warning">{{ result }}</span>
+            <span class="label label-warning">{% trans result %}</span>
           {% else %}
             {{ result }}
           {% endif %}
diff --git a/plinth/modules/dynamicdns/forms.py b/plinth/modules/dynamicdns/forms.py
index 918bf7f5e..e4344a85a 100644
--- a/plinth/modules/dynamicdns/forms.py
+++ b/plinth/modules/dynamicdns/forms.py
@@ -7,12 +7,14 @@ from django import forms
 from django.core import validators
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy
+
 from plinth import cfg
 from plinth.utils import format_lazy
 
 
 class TrimmedCharField(forms.CharField):
     """Trim the contents of a CharField."""
+
     def clean(self, value):
         """Clean and validate the field value"""
         if value:
@@ -59,11 +61,11 @@ class ConfigureForm(forms.Form):
     help_user = \
         ugettext_lazy('The username that was used when the account was '
                       'created.')
-    """ToDo: sync this list with the html template file"""
-    provider_choices = (('GnuDIP', 'GnuDIP'), ('noip', 'noip.com'),
-                        ('selfhost', 'selfhost.bz'), ('freedns',
-                                                      'freedns.afraid.org'),
-                        ('other', 'other update URL'))
+
+    provider_choices = (('GnuDIP', ugettext_lazy('GnuDIP')),
+                        ('noip', 'noip.com'), ('selfhost', 'selfhost.bz'),
+                        ('freedns', 'freedns.afraid.org'),
+                        ('other', ugettext_lazy('other update URL')))
 
     enabled = forms.BooleanField(label=ugettext_lazy('Enable Dynamic DNS'),
                                  required=False)
diff --git a/plinth/modules/i2p/views.py b/plinth/modules/i2p/views.py
index 181316d1a..31a97e13f 100644
--- a/plinth/modules/i2p/views.py
+++ b/plinth/modules/i2p/views.py
@@ -3,7 +3,7 @@
 Views for I2P application.
 """
 
-from django.utils.translation import ugettext as _
+from django.utils.translation import ugettext_lazy as _
 
 from plinth.views import AppView
 
diff --git a/plinth/modules/names/templates/names.html b/plinth/modules/names/templates/names.html
index 126e18617..c3ea506d4 100644
--- a/plinth/modules/names/templates/names.html
+++ b/plinth/modules/names/templates/names.html
@@ -11,9 +11,9 @@
   <table class="table table-bordered table-condensed table-striped names-table">
     <thead>
       <tr>
-        <th>Type</th>
-        <th class="names-domain-column">Domain Name</th>
-        <th>Services</th>
+        <th>{% trans "Type" %}</th>
+        <th class="names-domain-column">{% trans "Domain Name" %}</th>
+        <th>{% trans "Services" %}</th>
         <th></th>
       </tr>
     </thead>
diff --git a/plinth/modules/performance/__init__.py b/plinth/modules/performance/__init__.py
index 61c813e8c..0c67a98bb 100644
--- a/plinth/modules/performance/__init__.py
+++ b/plinth/modules/performance/__init__.py
@@ -22,12 +22,12 @@ managed_services = [
 managed_packages = ['cockpit-pcp']
 
 _description = [
-    ('Performance app allows you to collect, store and view information about '
-     'utilization of the hardware. This can give you basic insights into '
-     'usage patterns and whether the hardware is overloaded by users and '
-     'services.'),
-    ('Performance metrics are collected by Performance Co-Pilot and can be '
-     'viewed using the Cockpit app.'),
+    _('Performance app allows you to collect, store and view information '
+      'about utilization of the hardware. This can give you basic insights '
+      'into usage patterns and whether the hardware is overloaded by users '
+      'and services.'),
+    _('Performance metrics are collected by Performance Co-Pilot and can be '
+      'viewed using the Cockpit app.'),
 ]
 
 app = None
diff --git a/plinth/modules/radicale/forms.py b/plinth/modules/radicale/forms.py
index 6536b9e92..0ce96e0f2 100644
--- a/plinth/modules/radicale/forms.py
+++ b/plinth/modules/radicale/forms.py
@@ -27,5 +27,6 @@ CHOICES = [
 
 class RadicaleForm(forms.Form):
     """Specialized configuration form for radicale service."""
-    access_rights = forms.ChoiceField(choices=CHOICES, required=True,
+    access_rights = forms.ChoiceField(label=_('Access rights'),
+                                      choices=CHOICES, required=True,
                                       widget=forms.RadioSelect())
diff --git a/plinth/modules/users/forms.py b/plinth/modules/users/forms.py
index 91c469fff..bebb77b74 100644
--- a/plinth/modules/users/forms.py
+++ b/plinth/modules/users/forms.py
@@ -65,6 +65,7 @@ class UsernameValidator(validators.RegexValidator):
 
 
 USERNAME_FIELD = forms.CharField(
+    label=ugettext_lazy('Username'),
     max_length=150, validators=[UsernameValidator()],
     help_text=ugettext_lazy('Required. 150 characters or fewer. English '
                             'letters, digits and @/./-/_ only.'))