diff --git a/pkgs/development/ocaml-modules/ocsigen-server/conduit.patch b/pkgs/development/ocaml-modules/ocsigen-server/conduit.patch
new file mode 100644
index 000000000000..5aaac2407e32
--- /dev/null
+++ b/pkgs/development/ocaml-modules/ocsigen-server/conduit.patch
@@ -0,0 +1,14 @@
+diff --git a/src/server/ocsigen_cohttp.ml b/src/server/ocsigen_cohttp.ml
+index 66895339..edbfcbf2 100644
+--- a/src/server/ocsigen_cohttp.ml
++++ b/src/server/ocsigen_cohttp.ml
+@@ -105,7 +105,8 @@ let handler ~ssl ~address ~port ~connector (flow, conn) request body =
+   let rec getsockname = function
+     | `TCP (ip, port) -> Unix.ADDR_INET (Ipaddr_unix.to_inet_addr ip, port)
+     | `Unix_domain_socket path -> Unix.ADDR_UNIX path
+-    | `TLS (_, edn) -> getsockname edn
++    | `TLS (_, edn) -> getsockname (edn :> Conduit_lwt_unix.endp)
++    | `TLS_tunnel _ -> raise (Failure "TLS tunnel not supported")
+     | `Unknown err -> raise (Failure ("resolution failed: " ^ err))
+     | `Vchan_direct _ -> raise (Failure "VChan not supported")
+     | `Vchan_domain_socket _ -> raise (Failure "VChan not supported")
diff --git a/pkgs/development/ocaml-modules/ocsigen-server/default.nix b/pkgs/development/ocaml-modules/ocsigen-server/default.nix
index e55fd1c05088..2e758c0545bf 100644
--- a/pkgs/development/ocaml-modules/ocsigen-server/default.nix
+++ b/pkgs/development/ocaml-modules/ocsigen-server/default.nix
@@ -64,6 +64,8 @@ buildDunePackage rec {
     hash = "sha256-T3bgPZpDO6plgebLJDBtBuR2eR/bN3o24UAUv1VwgtI=";
   };
 
+  patches = [ ./conduit.patch ];
+
   nativeBuildInputs = [
     makeWrapper
     which