diff --git a/pkgs/development/python-modules/pytest-cov/default.nix b/pkgs/development/python-modules/pytest-cov/default.nix
index 52c592c86912..971b12dc01c7 100644
--- a/pkgs/development/python-modules/pytest-cov/default.nix
+++ b/pkgs/development/python-modules/pytest-cov/default.nix
@@ -4,6 +4,7 @@
 , pytest
 , coverage
 , toml
+, tomli
 }:
 
 buildPythonPackage rec {
@@ -17,7 +18,7 @@ buildPythonPackage rec {
 
   buildInputs = [ pytest ];
 
-  propagatedBuildInputs = [ coverage toml ];
+  propagatedBuildInputs = [ coverage toml tomli ];
 
   # xdist related tests fail with the following error
   # OSError: [Errno 13] Permission denied: 'py/_code'