diff --git a/pkgs/development/python-modules/pytest/default.nix b/pkgs/development/python-modules/pytest/default.nix
index 0e3f89fa152..9c158a55b81 100644
--- a/pkgs/development/python-modules/pytest/default.nix
+++ b/pkgs/development/python-modules/pytest/default.nix
@@ -1,9 +1,9 @@
 { stdenv, buildPythonPackage, fetchPypi, attrs, hypothesis, py
 , setuptools_scm, setuptools, six, pluggy, funcsigs, isPy3k, more-itertools
-, atomicwrites, mock, writeText
+, atomicwrites, mock, writeText, pathlib2
 }:
 buildPythonPackage rec {
-  version = "3.6.3";
+  version = "3.7.1";
   pname = "pytest";
 
   preCheck = ''
@@ -13,13 +13,13 @@ buildPythonPackage rec {
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "0453c8676c2bee6feb0434748b068d5510273a916295fd61d306c4f22fbfd752";
+    sha256 = "86a8dbf407e437351cef4dba46736e9c5a6e3c3ac71b2e942209748e76ff2086";
   };
 
   checkInputs = [ hypothesis mock ];
   buildInputs = [ setuptools_scm ];
   propagatedBuildInputs = [ attrs py setuptools six pluggy more-itertools atomicwrites]
-    ++ (stdenv.lib.optional (!isPy3k) funcsigs);
+    ++ stdenv.lib.optionals (!isPy3k) [ funcsigs pathlib2 ];
 
   checkPhase = ''
     runHook preCheck
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 322f831b4b5..20d665d7ed6 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -1832,15 +1832,15 @@ in {
     };
   };
 
-  pytest = self.pytest_36;
+  pytest = self.pytest_37;
 
-  pytest_36 = callPackage ../development/python-modules/pytest {
+  pytest_37 = callPackage ../development/python-modules/pytest {
     # hypothesis tests require pytest that causes dependency cycle
     hypothesis = self.hypothesis.override { doCheck = false; };
   };
 
   # Needed for celery
-  pytest_32 = self.pytest_36.overridePythonAttrs( oldAttrs: rec {
+  pytest_32 = self.pytest_37.overridePythonAttrs( oldAttrs: rec {
     version = "3.2.5";
     src = oldAttrs.src.override {
       inherit version;