diff --git a/pkgs/tools/misc/opentimestamps-client/default.nix b/pkgs/tools/misc/opentimestamps-client/default.nix
index 3fbd874503de..94984c57e49c 100644
--- a/pkgs/tools/misc/opentimestamps-client/default.nix
+++ b/pkgs/tools/misc/opentimestamps-client/default.nix
@@ -1,5 +1,6 @@
 { lib, buildPythonApplication, fetchFromGitHub, isPy3k
-, opentimestamps, appdirs, GitPython, pysocks }:
+, opentimestamps, appdirs, GitPython, pysocks, fetchpatch, git
+}:
 
 buildPythonApplication rec {
   pname = "opentimestamps-client";
@@ -15,6 +16,15 @@ buildPythonApplication rec {
     sha256 = "05m8nllqad3k69mvby5q08y22i0wrj84gqifdgcldimrrn1i00xp";
   };
 
+  patches = [
+    (fetchpatch {
+      url = "https://github.com/opentimestamps/opentimestamps-client/commit/1b328269ceee66916e9a639e8d5d7d13cd70d5d8.patch";
+      sha256 = "0bd3yalyvk5n4sflw9zilpay5k653ybdgkkfppyrk7c8z3i81hbl";
+    })
+  ];
+
+  checkInputs = [ git ];
+
   propagatedBuildInputs = [ opentimestamps appdirs GitPython pysocks ];
 
   meta = {