1 files changed, 1 insertions, 1 deletions
diff --git a/nixpkgs/pkgs/data/sgml+xml/schemas/xml-dtd/docbook-ebnf/default.nix b/nixpkgs/pkgs/data/sgml+xml/schemas/xml-dtd/docbook-ebnf/default.nix
index 3d8e16443dbf..a3b7067b2a42 100644
--- a/nixpkgs/pkgs/data/sgml+xml/schemas/xml-dtd/docbook-ebnf/default.nix
+++ b/nixpkgs/pkgs/data/sgml+xml/schemas/xml-dtd/docbook-ebnf/default.nix
@@ -4,7 +4,7 @@ stdenv.mkDerivation {
   name = "docbook-xml-ebnf-1.2b1";
 
   dtd = fetchurl {
-    url = http://www.docbook.org/xml/ebnf/1.2b1/dbebnf.dtd;
+    url = "http://www.docbook.org/xml/ebnf/1.2b1/dbebnf.dtd";
     sha256 = "0min5dsc53my13b94g2yd65q1nkjcf4x1dak00bsc4ckf86mrx95";
   };
   catalog = ./docbook-ebnf.cat;