diff --git a/pkgs/development/python-modules/certifi/default.nix b/pkgs/development/python-modules/certifi/default.nix
index 0aa2a321b832..c80ba08503d4 100644
--- a/pkgs/development/python-modules/certifi/default.nix
+++ b/pkgs/development/python-modules/certifi/default.nix
@@ -30,16 +30,15 @@ buildPythonPackage rec {
     ln -snvf "${cacert}/etc/ssl/certs/ca-bundle.crt" "certifi/cacert.pem"
   '';
 
+  propagatedNativeBuildInputs = [
+    # propagate cacerts setup-hook to set up `NIX_SSL_CERT_FILE`
+    cacert
+  ];
+
   checkInputs = [
     pytestCheckHook
   ];
 
-  preCheck = ''
-    # NIX_SSL_CERT_FILE is set to /no-cert-file.crt during build, which
-    # breaks the tests
-    unset NIX_SSL_CERT_FILE
-  '';
-
   pythonImportsCheck = [
     "certifi"
   ];
diff --git a/pkgs/development/python-modules/sphinx/default.nix b/pkgs/development/python-modules/sphinx/default.nix
index 5edfaa251515..5a27f04bd0ee 100644
--- a/pkgs/development/python-modules/sphinx/default.nix
+++ b/pkgs/development/python-modules/sphinx/default.nix
@@ -95,9 +95,6 @@ buildPythonPackage rec {
 
   preCheck = ''
     export HOME=$(mktemp -d)
-
-    # Unset dummy cert file path set in stdenv, that confuses certifi
-    unset NIX_SSL_CERT_FILE
   '';
 
   disabledTests = [