diff --git a/pkgs/by-name/mq/mqtt-exporter/package.nix b/pkgs/by-name/mq/mqtt-exporter/package.nix
index b9d3ba617d4d..8ae7fe04a6aa 100644
--- a/pkgs/by-name/mq/mqtt-exporter/package.nix
+++ b/pkgs/by-name/mq/mqtt-exporter/package.nix
@@ -16,6 +16,12 @@ python3.pkgs.buildPythonApplication rec {
     hash = "sha256-z2y43sRlwgy3Bwhu8rvlTkf6HOT+v8kjo5FT3lo5CEA=";
   };
 
+  postPatch = ''
+    # https://github.com/kpetremann/mqtt-exporter/pull/117
+    substituteInPlace pyproject.toml \
+      --replace-fail  "mqtt_exporter.main:main" "mqtt_exporter.main:main_mqtt_exporter"
+  '';
+
   build-system = with python3.pkgs; [ setuptools ];
 
   dependencies = with python3.pkgs; [