diff --git a/pkgs/development/python-modules/pyhomematic/default.nix b/pkgs/development/python-modules/pyhomematic/default.nix
index 1191b09ec38..be6fb7c8bb6 100644
--- a/pkgs/development/python-modules/pyhomematic/default.nix
+++ b/pkgs/development/python-modules/pyhomematic/default.nix
@@ -14,6 +14,9 @@ buildPythonPackage rec {
     sha256 = "1g181x2mrhxcaswr6vi2m7if97wv4rf2g2pny60334sciga8njfz";
   };
 
+  # Unreliable timing: https://github.com/danielperna84/pyhomematic/issues/126
+  doCheck = false;
+
   meta = with stdenv.lib; {
     description = "Python 3 Interface to interact with Homematic devices";
     homepage = https://github.com/danielperna84/pyhomematic;