diff --git a/debian/changelog b/debian/changelog
index 0d5f139da41213611345cb4afb62327b6dc7eff5..0b5f5598b1a7931583e18a3fe5c598e49c9f26f6 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -11,6 +11,7 @@ python-mkdocs (1.0.4+dfsg-2) UNRELEASED; urgency=medium
   * Adopt link target of font-awesome files
     - fonts-font-awesome 5.0.10+really4.7.0~dfsg-2 provides only OpenType
       and TrueType under /usr/share/fonts/
+  * Fix FTBFS (Closes: #963337)
 
  -- Ondřej Nový <onovy@debian.org>  Sat, 20 Jul 2019 00:06:32 +0200
 
diff --git a/debian/patches/0008-Fix-FTBFS.patch b/debian/patches/0008-Fix-FTBFS.patch
new file mode 100644
index 0000000000000000000000000000000000000000..a3c19566911e999bb5d80aff090217ff59d09d4e
--- /dev/null
+++ b/debian/patches/0008-Fix-FTBFS.patch
@@ -0,0 +1,18 @@
+Description: Mocking 'io.open' does not work at build time
+ If we remove the mock.patch('io.open', ...) test_build_extra_template
+ can be executed successfully.
+
+Author: Lukas Märdian <lukas.maerdian@canonical.com>
+Bug-Debian: https://bugs.debian.org/963337
+
+--- python-mkdocs-1.0.4+dfsg.orig/mkdocs/tests/build_tests.py
++++ python-mkdocs-1.0.4+dfsg/mkdocs/tests/build_tests.py
+@@ -228,7 +228,6 @@ class BuildTests(PathAssertionMixin, Log
+ 
+     # Test build._build_extra_template
+ 
+-    @mock.patch('io.open', mock.mock_open(read_data='template content'))
+     def test_build_extra_template(self):
+         cfg = load_config()
+         files = Files([
+
diff --git a/debian/patches/series b/debian/patches/series
index 0ea751e33c02d9e04514045a008ac818e233bffa..d948a70dfe038fec5b396e3932685781bfbe2816 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -5,3 +5,4 @@
 0005-Disable-the-Markdown-GitHub-links-extension.patch
 0006-Do-not-assert-that-fonts-directory-exists.patch
 0007-Disable-non-English-search-support.patch
+0008-Fix-FTBFS.patch