diff --git a/gnu/local.mk b/gnu/local.mk
index 060de25357..ca415ec48f 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -954,6 +954,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/util-linux-tests.patch			\
   %D%/packages/patches/upower-builddir.patch			\
   %D%/packages/patches/valgrind-enable-arm.patch		\
+  %D%/packages/patches/vdirsyncer-test-suite-slow-machines.patch	\
   %D%/packages/patches/vim-CVE-2017-5953.patch			\
   %D%/packages/patches/vorbis-tools-CVE-2014-9638+CVE-2014-9639.patch		\
   %D%/packages/patches/vorbis-tools-CVE-2014-9640.patch		\
diff --git a/gnu/packages/dav.scm b/gnu/packages/dav.scm
index dd03d8964b..908b336f8c 100644
--- a/gnu/packages/dav.scm
+++ b/gnu/packages/dav.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2015, 2016 Leo Famulari <leo@famulari.name>
+;;; Copyright © 2015, 2016, 2017 Leo Famulari <leo@famulari.name>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -21,6 +21,7 @@ (define-module (gnu packages dav)
   #:use-module (guix download)
   #:use-module (guix licenses)
   #:use-module (guix packages)
+  #:use-module (gnu packages)
   #:use-module (gnu packages python))
 
 (define-public radicale
@@ -58,6 +59,8 @@ (define-public vdirsyncer
     (source (origin
              (method url-fetch)
              (uri (pypi-uri name version))
+             (patches
+               (search-patches "vdirsyncer-test-suite-slow-machines.patch"))
              (sha256
               (base32
                "044f01fjd8dpz4y9dm3qcc1a8cihcxxbr1sz6y6fkvglpb6k85y5"))))
diff --git a/gnu/packages/patches/vdirsyncer-test-suite-slow-machines.patch b/gnu/packages/patches/vdirsyncer-test-suite-slow-machines.patch
new file mode 100644
index 0000000000..03093e8330
--- /dev/null
+++ b/gnu/packages/patches/vdirsyncer-test-suite-slow-machines.patch
@@ -0,0 +1,42 @@
+Fix test failures caused by some build machines running more slowly than
+expected, which manifest like this:
+
+------
+>       raise FailedHealthCheck(message)
+E       hypothesis.errors.FailedHealthCheck: Data generation is extremely slow: Only produced 4 valid examples in 1.08 seconds (1 invalid ones and 0 exceeded maximum size). Try decreasing size of the data you're generating (with e.g.average_size or max_leaves parameters).
+E       See http://hypothesis.readthedocs.org/en/latest/healthchecks.html for more information about this. If you want to disable just this health check, add HealthCheck.too_slowto the suppress_health_check settings for this test.
+
+/gnu/store/b8d1r8bilvm3jkncgrpvmg3dni9cgcr1-python-hypothesis-3.1.0/lib/python3.5/site-packages/hypothesis/core.py:296: FailedHealthCheck
+------
+
+Patch copied from upstream source repository:
+
+https://github.com/pimutils/vdirsyncer/commit/10490a12f13f03495e0945eb9d45d7aed9ab0a6c
+
+From 10490a12f13f03495e0945eb9d45d7aed9ab0a6c Mon Sep 17 00:00:00 2001
+From: Markus Unterwaditzer <markus@unterwaditzer.net>
+Date: Sat, 18 Feb 2017 15:45:06 +0100
+Subject: [PATCH] Unconditionally disable HealthCheck.too_slow
+
+---
+ tests/conftest.py | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/tests/conftest.py b/tests/conftest.py
+index e0a07d5..3afd7cd 100644
+--- a/tests/conftest.py
++++ b/tests/conftest.py
+@@ -26,10 +26,12 @@ def benchmark():
+ else:
+     del pytest_benchmark
+ 
++
++settings.suppress_health_check = [HealthCheck.too_slow]
++
+ settings.register_profile("ci", settings(
+     max_examples=1000,
+     verbosity=Verbosity.verbose,
+-    suppress_health_check=[HealthCheck.too_slow]
+ ))
+ settings.register_profile("deterministic", settings(
+     derandomize=True,