diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index 01f4fba83b75..0212974b5d3b 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -4611,7 +4611,7 @@ let
     pname = "Data-Serializer";
     version = "0.65";
     src = fetchurl {
-      url = mirror://cpan/authors/id/N/NE/NEELY/Data-Serializer-0.65.tar.gz;
+      url = "mirror://cpan/authors/id/N/NE/NEELY/Data-Serializer-0.65.tar.gz";
       sha256 = "048zjy8valnil8yawa3vrxr005rz95gpfwvmy2jq0g830195l58j";
     };
     meta = {