diff --git a/templates/404.html b/templates/404.html
new file mode 100644
index 000000000..b4e9a30d1
--- /dev/null
+++ b/templates/404.html
@@ -0,0 +1,36 @@
+{% extends 'login_nav.html' %}
+{% comment %}
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+{% endcomment %}
+
+{% block title_block %}
+404
+{% endblock %}
+
+{% block main_block %}
+
+<p>Requested page {{ request_path }} was not found.</p>
+
+<p>If you believe this missing page should exist, please file a bug with either
+   the Plinth project (<a href="https://github.com/NickDaly/Plinth/issues">it
+   has an issue tracker</a>) or the people responsible for the module you are
+   trying to access.</p>
+
+<p>Sorry for the mistake.</p>
+
+{% endblock %}
diff --git a/templates/500.html b/templates/500.html
new file mode 100644
index 000000000..485f3df3c
--- /dev/null
+++ b/templates/500.html
@@ -0,0 +1,32 @@
+{% extends 'login_nav.html' %}
+{% comment %}
+#
+# This file is part of Plinth.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+{% endcomment %}
+
+{% block title_block %}
+500
+{% endblock %}
+
+{% block main_block %}
+
+<p>This is an internal error and not something you caused or can fix.  Please
+   report the error on
+   the <a href="https://github.com/NickDaly/Plinth/issues">bug tracker</a> so we
+   can fix it.</p>
+
+{% endblock %}