diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index bfe04bb37118..253762b6c69b 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -1415,7 +1415,7 @@ let
     pname = "Cache-Memcached-Fast";
     version = "0.26";
     src = fetchurl {
-      url = mirror://cpan/authors/id/R/RA/RAZ/Cache-Memcached-Fast-0.26.tar.gz;
+      url = "mirror://cpan/authors/id/R/RA/RAZ/Cache-Memcached-Fast-0.26.tar.gz";
       sha256 = "16m0xafidycrlcvbv3zmbr5pzvqyqyr2qb0khpry99nc4bcld3jy";
     };
     meta = {