diff --git a/opium/src/router.ml b/opium/src/router.ml
index d82b0849..f7281d95 100644
--- a/opium/src/router.ml
+++ b/opium/src/router.ml
@@ -3,12 +3,14 @@ module Route = struct
 
   type t =
     | Nil
+    | Full_splat
     | Literal of string * t
     | Param of string option * t
 
   let rec sexp_of_t (t : t) : Sexplib0.Sexp.t =
     match t with
     | Nil -> Atom "Nil"
+    | Full_splat -> Atom "Full_splat"
     | Literal (x, y) -> List [ Atom x; sexp_of_t y ]
     | Param (x, y) ->
       let x : Sexplib0.Sexp.t =
@@ -23,6 +25,7 @@ module Route = struct
 
   let rec parse_tokens params tokens =
     match tokens with
+    | [ "**" ] -> Full_splat
     | [] | [ "" ] -> Nil
     | token :: tokens ->
       if token = ""
@@ -86,6 +89,7 @@ module Params = struct
   let create route captured =
     let rec loop acc (route : Route.t) captured =
       match route, captured with
+      | Full_splat, _ -> assert false
       | Nil, [] -> acc
       | Literal (_, route), _ -> loop acc route captured
       | Param (None, route), p :: captured ->
@@ -159,6 +163,7 @@ let match_url t url =
 let match_route t route =
   let rec loop t (route : Route.t) =
     match route with
+    | Full_splat -> assert false
     | Nil ->
       (match t.data with
       | None -> []
@@ -190,6 +195,7 @@ let match_route t route =
 let add_no_check t orig_route a =
   let rec loop t (route : Route.t) =
     match route with
+    | Full_splat -> assert false
     | Nil -> { empty with data = Some (a, orig_route) }
     | Literal (lit, route) ->
       let literal =
diff --git a/opium/test/opium_router_tests.ml b/opium/test/opium_router_tests.ml
index 5b88edf6..8c282a57 100644
--- a/opium/test/opium_router_tests.ml
+++ b/opium/test/opium_router_tests.ml
@@ -37,6 +37,16 @@ let%expect_test "duplicate paramters" =
   [%expect {| [FAIL] invalid route duplicate parameter "bar" |}]
 ;;
 
+let%expect_test "splat in the middle is wrong" =
+  valid_route "/foo/**/foo";
+  [%expect {| [FAIL] invalid route double splat allowed only in the end |}]
+;;
+
+let%expect_test "splat at the end" =
+  valid_route "/foo/**";
+  [%expect {| [PASS] valid route |}]
+;;
+
 let test_match_url router url =
   match Router.match_url router url with
   | None -> print_endline "no match"
@@ -93,7 +103,7 @@ let%expect_test "ambiguity in routes" =
   (Failure "duplicate routes")
   Raised at Stdlib.failwith in file "stdlib.ml", line 29, characters 17-33
   Called from Stdlib__list.fold_left in file "list.ml", line 121, characters 24-34
-  Called from Opium_tests__Opium_router_tests.(fun) in file "opium/test/opium_router_tests.ml", line 85, characters 2-49
+  Called from Opium_tests__Opium_router_tests.(fun) in file "opium/test/opium_router_tests.ml", line 95, characters 2-49
   Called from Expect_test_collector.Make.Instance.exec in file "collector/expect_test_collector.ml", line 244, characters 12-19 |}]
 ;;
 
@@ -109,7 +119,7 @@ let%expect_test "ambiguity in routes 2" =
   (Failure "duplicate routes")
   Raised at Stdlib.failwith in file "stdlib.ml", line 29, characters 17-33
   Called from Stdlib__list.fold_left in file "list.ml", line 121, characters 24-34
-  Called from Opium_tests__Opium_router_tests.(fun) in file "opium/test/opium_router_tests.ml", line 101, characters 2-43
+  Called from Opium_tests__Opium_router_tests.(fun) in file "opium/test/opium_router_tests.ml", line 111, characters 2-43
   Called from Expect_test_collector.Make.Instance.exec in file "collector/expect_test_collector.ml", line 244, characters 12-19 |}]
 ;;