diff --git a/pkgs/development/python-modules/cryptography/default.nix b/pkgs/development/python-modules/cryptography/default.nix
index 2a8736e29de3..52244ae4d961 100644
--- a/pkgs/development/python-modules/cryptography/default.nix
+++ b/pkgs/development/python-modules/cryptography/default.nix
@@ -20,12 +20,10 @@
 , hypothesis
 }:
 
-let
-  version = "2.3";
-in assert version == cryptography_vectors.version; buildPythonPackage rec {
+buildPythonPackage rec {
   # also bump cryptography_vectors
   pname = "cryptography";
-  inherit version;
+  version = "2.3";
 
   src = fetchPypi {
     inherit pname version;
@@ -64,4 +62,4 @@ in assert version == cryptography_vectors.version; buildPythonPackage rec {
   # IOKit's dependencies are inconsistent between OSX versions, so this is the best we
   # can do until nix 1.11's release
   __impureHostDeps = [ "/usr/lib" ];
-}
\ No newline at end of file
+}