diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index f38b366a655..bfca26e179c 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -8463,7 +8463,7 @@ let
     pname = "GnuPG-Interface";
     version = "1.00";
     src = fetchurl {
-      url = mirror://cpan/authors/id/J/JE/JESSE/GnuPG-Interface-1.00.tar.gz;
+      url = "mirror://cpan/authors/id/J/JE/JESSE/GnuPG-Interface-1.00.tar.gz";
       sha256 = "97e9c809491a061b2e99fb4e50c7bf74eb42e1deb11c64b081b21b4dbe6aec2f";
     };
     buildInputs = [ pkgs.which pkgs.gnupg1compat ];