diff --git a/pkgs/applications/science/math/pari/default.nix b/pkgs/applications/science/math/pari/default.nix
index 32e4d81acec..919feedec04 100644
--- a/pkgs/applications/science/math/pari/default.nix
+++ b/pkgs/applications/science/math/pari/default.nix
@@ -1,17 +1,21 @@
-{ stdenv, fetchurl
-, gmp, readline, libX11, tex, perl
+{ stdenv
+, fetchurl
+, gmp
+, readline
+, libX11
+, tex
+, perl
 , withThread ? true, libpthreadstubs
 }:
 
 assert withThread -> libpthreadstubs != null;
 
 stdenv.mkDerivation rec {
-
-  name = "pari-${version}";
+  pname = "pari";
   version = "2.11.1";
 
   src = fetchurl {
-    url = "https://pari.math.u-bordeaux.fr/pub/pari/unix/${name}.tar.gz";
+    url = "https://pari.math.u-bordeaux.fr/pub/pari/unix/${pname}-${version}.tar.gz";
     sha256 = "1jfax92jpydjd02fwl30r6b8kfzqqd6sm4yx94gidyz9lqjb7a94";
   };