diff --git a/compiler/tests-full/dune b/compiler/tests-full/dune
index 5effacad3b..5f55bb9cd0 100644
--- a/compiler/tests-full/dune
+++ b/compiler/tests-full/dune
@@ -1,7 +1,9 @@
 (rule
  (targets stdlib.cma.js)
  (enabled_if
-  (= %{ocaml_version} "5.2.0"))
+  (and
+   (>= %{ocaml_version} "5.2")
+   (< %{ocaml_version} "5.3")))
  (action
   (run
    %{bin:js_of_ocaml}
@@ -14,7 +16,9 @@
 (rule
  (targets stdlib.cma.output.js)
  (enabled_if
-  (= %{ocaml_version} "5.2.0"))
+  (and
+   (>= %{ocaml_version} "5.2")
+   (< %{ocaml_version} "5.3")))
  (action
   (with-stdout-to
    %{targets}
@@ -23,7 +27,9 @@
 (rule
  (alias runtest)
  (enabled_if
-  (= %{ocaml_version} "5.2.0"))
+  (and
+   (>= %{ocaml_version} "5.2")
+   (< %{ocaml_version} "5.3")))
  (action
   (diff stdlib.cma.expected.js stdlib.cma.output.js)))
 
diff --git a/compiler/tests-full/stdlib.cma.expected.js b/compiler/tests-full/stdlib.cma.expected.js
index 099faef92e..a314cd8eeb 100644
--- a/compiler/tests-full/stdlib.cma.expected.js
+++ b/compiler/tests-full/stdlib.cma.expected.js
@@ -1121,8 +1121,8 @@
     caml_maybe_attach_backtrace = runtime.caml_maybe_attach_backtrace,
     caml_wrap_exception = runtime.caml_wrap_exception,
     global_data = runtime.caml_get_global_data(),
-    ocaml_version = "5.2.0",
-    ocaml_release = [0, 5, 2, 0, 0],
+    ocaml_version = "5.2.1",
+    ocaml_release = [0, 5, 2, 1, 0],
     Stdlib = global_data.Stdlib,
     executable_name =
        /*<<sys.ml.in:36:22>>*/ runtime.caml_sys_executable_name(0),
@@ -23571,26 +23571,26 @@
      /*<<gc.ml:115:21>>*/ return caml_call2(Stdlib_Atomic[4], a, 0) /*<<gc.ml:115:39>>*/ ;
    }
    function create_alarm(f){
-    var _y_ =  /*<<gc.ml:118:24>>*/ caml_call1(Stdlib_Atomic[1], 1);
-     /*<<gc.ml:119:2>>*/ caml_call1
+    var alarm =  /*<<gc.ml:119:14>>*/ caml_call1(Stdlib_Atomic[1], 1);
+     /*<<gc.ml:120:2>>*/ caml_call1
      (Stdlib_Domain[6],
       function(param){
-        /*<<gc.ml:119:28>>*/ return delete_alarm(_y_) /*<<gc.ml:119:52>>*/ ;
+        /*<<gc.ml:120:28>>*/ return delete_alarm(alarm) /*<<gc.ml:120:46>>*/ ;
       });
-     /*<<gc.ml:120:26>>*/ return _y_;
-    /*<<gc.ml:121:13>>*/ }
+     /*<<gc.ml:122:26>>*/ return alarm;
+    /*<<gc.ml:123:7>>*/ }
    var
     null_tracker =
        /*<<?>>*/ [0,
-       function(param){ /*<<gc.ml:143:30>>*/ return 0; /*<<gc.ml:143:34>>*/ },
-       function(param){ /*<<gc.ml:144:30>>*/ return 0; /*<<gc.ml:144:34>>*/ },
-       function(param){ /*<<gc.ml:145:26>>*/ return 0; /*<<gc.ml:145:30>>*/ },
-       function(param){ /*<<gc.ml:146:32>>*/ return 0; /*<<gc.ml:146:34>>*/ },
-       function(param){ /*<<gc.ml:147:32>>*/ return 0; /*<<gc.ml:147:34>>*/ }];
+       function(param){ /*<<gc.ml:145:30>>*/ return 0; /*<<gc.ml:145:34>>*/ },
+       function(param){ /*<<gc.ml:146:30>>*/ return 0; /*<<gc.ml:146:34>>*/ },
+       function(param){ /*<<gc.ml:147:26>>*/ return 0; /*<<gc.ml:147:30>>*/ },
+       function(param){ /*<<gc.ml:148:32>>*/ return 0; /*<<gc.ml:148:34>>*/ },
+       function(param){ /*<<gc.ml:149:32>>*/ return 0; /*<<gc.ml:149:34>>*/ }];
    function start(sampling_rate, opt, tracker){
-    var callstack_size =  /*<<gc.ml:155:6>>*/ opt ? opt[1] : Stdlib[19];
-     /*<<gc.ml:158:6>>*/ return runtime.caml_memprof_start
-            (sampling_rate, callstack_size, tracker) /*<<gc.ml:158:50>>*/ ;
+    var callstack_size =  /*<<gc.ml:157:6>>*/ opt ? opt[1] : Stdlib[19];
+     /*<<gc.ml:160:6>>*/ return runtime.caml_memprof_start
+            (sampling_rate, callstack_size, tracker) /*<<gc.ml:160:50>>*/ ;
    }
    var
     Stdlib_Gc =
diff --git a/dune b/dune
index c68dad2d65..292467727b 100644
--- a/dune
+++ b/dune
@@ -46,4 +46,6 @@
     %{dep:VERSION}
     %{dep:tools/version/GIT-VERSION}))))
 
-(data_only_dirs _wikidoc doc-dev)
+(data_only_dirs _wikidoc doc-dev jane-street)
+
+(vendored_dirs)
diff --git a/runtime/wasm/effect.wat b/runtime/wasm/effect.wat
index 5bc8678f2a..c8932c2d9b 100644
--- a/runtime/wasm/effect.wat
+++ b/runtime/wasm/effect.wat
@@ -24,7 +24,7 @@
      (func $caml_fresh_oo_id (param (ref eq)) (result (ref eq))))
    (import "obj" "cont_tag" (global $cont_tag i32))
    (import "stdlib" "caml_named_value"
-      (func $caml_named_value (param (ref $string)) (result (ref null eq))))
+      (func $caml_named_value (param (ref eq)) (result (ref null eq))))
    (import "fail" "ocaml_exception" (tag $ocaml_exception (param (ref eq))))
    (import "fail" "javascript_exception"
       (tag $javascript_exception (param externref)))
diff --git a/runtime/wasm/jslib.wat b/runtime/wasm/jslib.wat
index b4468e8dea..b15f2809a7 100644
--- a/runtime/wasm/jslib.wat
+++ b/runtime/wasm/jslib.wat
@@ -77,7 +77,7 @@
    (import "fail" "caml_failwith_tag"
       (func $caml_failwith_tag (result (ref eq))))
    (import "stdlib" "caml_named_value"
-      (func $caml_named_value (param (ref $string)) (result (ref null eq))))
+      (func $caml_named_value (param (ref eq)) (result (ref null eq))))
    (import "obj" "caml_callback_1"
       (func $caml_callback_1
          (param (ref eq)) (param (ref eq)) (result (ref eq))))
@@ -89,6 +89,9 @@
       (func $jsstring_of_string (param (ref $string)) (result anyref)))
    (import "jsstring" "string_of_jsstring"
       (func $string_of_jsstring (param anyref) (result (ref $string))))
+   (import "jsstring" "jsstring_of_substring"
+      (func $jsstring_of_substring
+         (param (ref $string) i32 i32) (result anyref)))
    (import "int32" "caml_copy_int32"
       (func $caml_copy_int32 (param i32) (result (ref eq))))
    (import "int32" "Int32_val"
@@ -459,6 +462,16 @@
       (local.set $s (ref.cast (ref $string) (local.get 0)))
       (return (struct.new $js (call $jsstring_of_string (local.get $s)))))
 
+   (func (export "caml_jsstring_of_substring")
+      (param $s (ref eq)) (param $i (ref eq)) (param $l (ref eq))
+      (result (ref eq))
+      (return
+         (struct.new $js
+            (call $jsstring_of_substring
+               (ref.cast (ref $string) (local.get $s))
+               (i31.get_u (ref.cast (ref i31) (local.get $i)))
+               (i31.get_u (ref.cast (ref i31) (local.get $l)))))))
+
    (func $caml_jsbytes_of_string (export "caml_jsbytes_of_string")
       (param (ref eq)) (result (ref eq))
       (local $s (ref $string))
diff --git a/runtime/wasm/stdlib.wat b/runtime/wasm/stdlib.wat
index 89ca56e627..5176402152 100644
--- a/runtime/wasm/stdlib.wat
+++ b/runtime/wasm/stdlib.wat
@@ -79,7 +79,7 @@
             (br $loop))))
 
    (func $caml_named_value (export "caml_named_value")
-      (param $s (ref $string)) (result (ref null eq))
+      (param $s (ref eq)) (result (ref null eq))
       (block $not_found
          (return
             (struct.get $assoc 1
diff --git a/tools/ci_setup.ml b/tools/ci_setup.ml
index 8ec9bb034c..d64dfbc7fc 100644
--- a/tools/ci_setup.ml
+++ b/tools/ci_setup.ml
@@ -266,7 +266,7 @@ let () =
       let branch =
         if is_forked nm
         then
-          if List.mem nm [ "bonsai"; "virtual_dom"; "async_js" ]
+          if List.mem nm [ "bonsai"; "virtual_dom"; "async_js"; "zarith_stubs_js" ]
           then Some "jsoo-6"
           else Some "wasm"
         else None