diff --git a/pkgs/development/python-modules/thumbor/default.nix b/pkgs/development/python-modules/thumbor/default.nix
index ec33a5020d4..4ab443afbff 100644
--- a/pkgs/development/python-modules/thumbor/default.nix
+++ b/pkgs/development/python-modules/thumbor/default.nix
@@ -1,6 +1,8 @@
-{ buildPythonPackage, tornado, pycrypto, pycurl, pytz
-, pillow, derpconf, python_magic, pexif, libthumbor, opencv, webcolors
-, piexif, futures, statsd, thumborPexif, fetchPypi, isPy3k, lib
+{ buildPythonPackage, python, tornado, pycrypto, pycurl, pytz
+, pillow, derpconf, python_magic, libthumbor, webcolors
+, piexif, futures, statsd, thumborPexif, fetchFromGitHub, isPy3k, lib
+, mock, raven, nose, yanc, remotecv, pyssim, cairosvg1, preggy, opencv3
+, pkgs, coreutils
 }:
 
 buildPythonPackage rec {
@@ -9,16 +11,38 @@ buildPythonPackage rec {
 
   disabled = isPy3k; # see https://github.com/thumbor/thumbor/issues/1004
 
-  src = fetchPypi {
-    inherit pname version;
-    sha256 = "1icfnzwzi5lvnh576n7v3r819jaw15ph9ja2w3fwg5z9qs40xvl8";
+  # Tests aren't included in PyPI tarball so use GitHub instead
+  src = fetchFromGitHub {
+    owner = pname;
+    repo = pname;
+    rev = version;
+    sha256 = "1ys5ymwbvgh2ir85g9nyrzzf8vgi16j6pzzi53b0rgjx0kwlmnxg";
   };
 
   postPatch = ''
     substituteInPlace "setup.py" \
       --replace '"argparse",' "" ${lib.optionalString isPy3k ''--replace '"futures",' ""''}
+    substituteInPlace "tests/test_utils.py" \
+      --replace "/bin/ls" "${coreutils}/bin/ls"
+    substituteInPlace "tests/detectors/test_face_detector.py" \
+      --replace "./thumbor" "$out/lib/${python.libPrefix}/site-packages/thumbor"
+    substituteInPlace "tests/detectors/test_glasses_detector.py" \
+      --replace "./thumbor" "$out/lib/${python.libPrefix}/site-packages/thumbor"
   '';
 
+  checkInputs = [
+    nose
+    pyssim
+    preggy
+    mock
+    yanc
+    remotecv
+    cairosvg1
+    raven
+    pkgs.redis
+    pkgs.glibcLocales
+  ];
+
   propagatedBuildInputs = [
     tornado
     pycrypto
@@ -27,18 +51,26 @@ buildPythonPackage rec {
     pillow
     derpconf
     python_magic
-    pexif
     libthumbor
-    opencv
+    opencv3
     webcolors
     piexif
     statsd
+    pkgs.exiftool
+    pkgs.libjpeg
+    pkgs.ffmpeg
+    pkgs.gifsicle
   ] ++ lib.optionals (!isPy3k) [ futures thumborPexif ];
 
-  # disabled due to too many impure tests and issues with native modules in
-  # the pure testing environment. See https://github.com/NixOS/nixpkgs/pull/37147
-  # for further reference.
-  doCheck = false;
+  # Remove the source tree before running nosetests because otherwise nosetests
+  # uses that instead of the installed package. Is there some other way to
+  # achieve this?
+  checkPhase = ''
+    redis-server --port 6668 --requirepass hey_you &
+    rm -r thumbor
+    export LC_ALL="en_US.UTF-8"
+    nosetests -v --with-yanc -s tests/
+  '';
 
   meta = with lib; {
     description = "A smart imaging service";