diff --git a/pkgs/python-packages.nix b/pkgs/python-packages.nix
--- a/pkgs/python-packages.nix
+++ b/pkgs/python-packages.nix
@@ -315,13 +315,13 @@
     };
   };
   mercurial = super.buildPythonPackage {
-    name = "mercurial-4.0.1";
+    name = "mercurial-4.0.2";
     buildInputs = with self; [];
     doCheck = false;
     propagatedBuildInputs = with self; [];
     src = fetchurl {
-      url = "https://pypi.python.org/packages/f2/42/544e271b92b55588603f21f9671049d618ee12aef5aca6f7b7034c86187c/mercurial-4.0.1.tar.gz";
-      md5 = "22a9b1d7c0c06a53f0ae5b386d536d08";
+      url = "https://pypi.python.org/packages/85/1b/0296aacd697228974a473d2508f013532f987ed6b1bacfe5abd6d5be6332/mercurial-4.0.2.tar.gz";
+      md5 = "fa72a08e2723e4fa2a21c4e66437f3fa";
     };
     meta = {
       license = [ pkgs.lib.licenses.gpl1 pkgs.lib.licenses.gpl2Plus ];
diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ configobj==5.0.6
 dulwich==0.13.0
 hgsubversion==1.8.6
 infrae.cache==1.0.1
-mercurial==4.0.1
+mercurial==4.0.2
 msgpack-python==0.4.8
 pyramid==1.6.1
 pyramid-jinja2==2.5