diff --git a/pkgs/development/python-modules/fs/default.nix b/pkgs/development/python-modules/fs/default.nix
index ca4fb75af304..1d4326f74ee3 100644
--- a/pkgs/development/python-modules/fs/default.nix
+++ b/pkgs/development/python-modules/fs/default.nix
@@ -5,6 +5,7 @@
 , setuptools
 , six
 , appdirs
+, scandir ? null
 , backports_os ? null
 , typing ? null
 , pytz
@@ -35,6 +36,7 @@ buildPythonPackage rec {
   propagatedBuildInputs = [ six appdirs pytz setuptools ]
     ++ lib.optionals (!isPy3k) [ backports_os ]
     ++ lib.optionals (!pythonAtLeast "3.6") [ typing ]
+    ++ lib.optionals (!pythonAtLeast "3.5") [ scandir ]
     ++ lib.optionals (!pythonAtLeast "3.5") [ enum34 ];
 
   LC_ALL="en_US.utf-8";
diff --git a/pkgs/development/python-modules/pathlib2/default.nix b/pkgs/development/python-modules/pathlib2/default.nix
index c382f74ae22b..f0f0163652ca 100644
--- a/pkgs/development/python-modules/pathlib2/default.nix
+++ b/pkgs/development/python-modules/pathlib2/default.nix
@@ -3,6 +3,7 @@
 , fetchPypi
 , six
 , pythonOlder
+, scandir ? null
 , glibcLocales
 , mock
 , typing
@@ -18,7 +19,7 @@ buildPythonPackage rec {
   };
 
   propagatedBuildInputs = [ six ]
-    ++ lib.optionals (pythonOlder "3.5") [ typing ];
+    ++ lib.optionals (pythonOlder "3.5") [ scandir typing ];
   checkInputs = [ glibcLocales ]
     ++ lib.optional (pythonOlder "3.3") mock;