diff --git a/nbdkit.spec b/nbdkit.spec
index ba8e95e..cd060f1 100644
--- a/nbdkit.spec
+++ b/nbdkit.spec
@@ -103,6 +103,7 @@ BuildRequires:  python3-devel
 # Requires OCaml 4.02.2 which contains fix for
 # http://caml.inria.fr/mantis/view.php?id=6693
 BuildRequires:  ocaml >= 4.02.2
+BuildRequires:  ocaml-ocamldoc
 %endif
 BuildRequires:  ruby-devel
 BuildRequires:  tcl-devel