diff --git a/pkgs/development/python-modules/atomman/default.nix b/pkgs/development/python-modules/atomman/default.nix
index 7b32dc9b9ec6..a245c93e3618 100644
--- a/pkgs/development/python-modules/atomman/default.nix
+++ b/pkgs/development/python-modules/atomman/default.nix
@@ -11,20 +11,19 @@
 , phonopy
 , potentials
 , pymatgen
-, pytest
 , pytestCheckHook
 , pythonOlder
-, pythonAtLeast
 , requests
 , scipy
 , setuptools
 , toolz
+, wheel
 , xmltodict
 , pythonRelaxDepsHook
 }:
 
 buildPythonPackage rec {
-  version = "1.4.6";
+  version = "unstable-2023-07-28";
   pname = "atomman";
   format = "pyproject";
 
@@ -33,12 +32,13 @@ buildPythonPackage rec {
   src = fetchFromGitHub {
     owner = "usnistgov";
     repo = "atomman";
-    rev = "v${version}";
-    hash = "sha256-tcsxtFbBdMC6+ixzqhnR+5UNwcQmnPQSvuyNA2IYelI=";
+    rev = "b8af21a9285959d38ee26173081db1b4488401bc";
+    hash = "sha256-WfB+OY61IPprT6OCVHl8VA60p7lLVkRGuyYX+nm7bbA=";
   };
 
   nativeBuildInputs = [
     setuptools
+    wheel
     pythonRelaxDepsHook
   ];
 
@@ -70,7 +70,6 @@ buildPythonPackage rec {
     ase
     phonopy
     pymatgen
-    pytest
     pytestCheckHook
   ];