diff --git a/pkgs/development/python-modules/ffmpy/default.nix b/pkgs/development/python-modules/ffmpy/default.nix
index a14d17776dd4..00a8a73aadad 100644
--- a/pkgs/development/python-modules/ffmpy/default.nix
+++ b/pkgs/development/python-modules/ffmpy/default.nix
@@ -4,7 +4,7 @@
   buildPythonPackage,
   fetchFromGitHub,
   pythonOlder,
-  setuptools,
+  poetry-core,
   pytestCheckHook,
   go,
   ffmpeg-headless,
@@ -12,22 +12,24 @@
 
 buildPythonPackage rec {
   pname = "ffmpy";
-  version = "0.3.2";
+  version = "0.4.0";
   pyproject = true;
 
-  disabled = pythonOlder "3.6";
+  disabled = pythonOlder "3.8.1";
 
   src = fetchFromGitHub {
     owner = "Ch00k";
     repo = "ffmpy";
     rev = "refs/tags/${version}";
-    hash = "sha256-q41JjAWcIiD2nJck5Zzb/lhfIZ3xJGU1I2crsMN0T8Q=";
+    hash = "sha256-XWI0Hq4vf9Q0/dRzmu1B7EQHdQRkWaNJaBaqusWW7YM=";
   };
 
   postPatch = ''
     # default to store ffmpeg
     substituteInPlace ffmpy.py \
-      --replace-fail 'executable="ffmpeg",' 'executable="${ffmpeg-headless}/bin/ffmpeg",'
+      --replace-fail \
+        'executable: str = "ffmpeg",' \
+        'executable: str = "${ffmpeg-headless}/bin/ffmpeg",'
 
     #  The tests test a mock that does not behave like ffmpeg. If we default to the nix-store ffmpeg they fail.
     for fname in tests/*.py; do
@@ -37,7 +39,7 @@ buildPythonPackage rec {
 
   pythonImportsCheck = [ "ffmpy" ];
 
-  nativeBuildInputs = [ setuptools ];
+  nativeBuildInputs = [ poetry-core ];
 
   nativeCheckInputs = [
     pytestCheckHook
@@ -52,8 +54,8 @@ buildPythonPackage rec {
   # the vendored ffmpeg mock binary assumes FHS
   preCheck = ''
     rm -v tests/ffmpeg/ffmpeg
-    HOME=$(mktemp -d) go build -o ffmpeg tests/ffmpeg/ffmpeg.go
-    export PATH=".:$PATH"
+    echo Building tests/ffmpeg/ffmpeg...
+    HOME=$(mktemp -d) go build -o tests/ffmpeg/ffmpeg tests/ffmpeg/ffmpeg.go
   '';
 
   meta = with lib; {