diff --git a/pkgs/development/python-modules/guppy3/default.nix b/pkgs/development/python-modules/guppy3/default.nix
index 80b4a19019a3..5c102f10a551 100644
--- a/pkgs/development/python-modules/guppy3/default.nix
+++ b/pkgs/development/python-modules/guppy3/default.nix
@@ -7,15 +7,15 @@
 
 buildPythonPackage rec {
   pname = "guppy3";
-  version = "3.1.4";
+  version = "3.1.4.post1";
   format = "setuptools";
-  disabled = pythonOlder "3.6";
+  disabled = pythonOlder "3.8";
 
   src = fetchFromGitHub {
     owner = "zhuyifei1999";
     repo = pname;
-    rev = "v${version}";
-    hash = "sha256-RMWIP4tVSCCEQpr0kZvsN1HwL6rBcLuubfBl175eSNg=";
+    rev = "refs/tags/v${version}";
+    hash = "sha256-HHy57P6WEHZKygAbdjEh6XAApFlQueiYGr02eSQMWfc=";
   };
 
   propagatedBuildInputs = [ tkinter ];