diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index 2f96fa978ea..63e826841e9 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -6917,7 +6917,7 @@ let
     pname = "EV";
     version = "4.33";
     src = fetchurl {
-      url = mirror://cpan/authors/id/M/ML/MLEHMANN/EV-4.33.tar.gz;
+      url = "mirror://cpan/authors/id/M/ML/MLEHMANN/EV-4.33.tar.gz";
       sha256 = "4aee8391b88113b42187f91fd49245fdc8e9b193a15ac202f519caae2aa8ea35";
     };
     buildInputs = [ CanaryStability ];