diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index 62f7ad93c88..1cb835ecef4 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -7401,7 +7401,7 @@ let
     pname = "File-BOM";
     version = "0.18";
     src = fetchurl {
-      url = mirror://cpan/authors/id/M/MA/MATTLAW/File-BOM-0.18.tar.gz;
+      url = "mirror://cpan/authors/id/M/MA/MATTLAW/File-BOM-0.18.tar.gz";
       sha256 = "28edc43fcb118e11bc458c9ae889d56d388c1d9bc29997b00b1dffd8573823a3";
     };
     buildInputs = [ TestException ];