diff --git a/bundled/bundle.ml b/bundled/bundle.ml
index a29e8ec..625a785 100644
--- a/bundled/bundle.ml
+++ b/bundled/bundle.ml
@@ -162,7 +162,7 @@ let float version = if version < (4,07) then simple "Float"
     chain "Float" ["Array"; "ArrayLabels"]
 
 
-let effect = chain "Effect" ["Deep"; "Shallow"]
+let effekt = chain "Effect" ["Deep"; "Shallow"]
 let semaphore = chain "Semaphore" ["Binary"; "Counting"]
 let domain = chain "Domain" ["DLS"]
 
@@ -179,7 +179,7 @@ let simple_stdlib v = Dict.of_list @@
   @ in_between v (4,12) (5,0) [ simple "CamlinternalAtomic"]
   @ after v (4,14) [simple "In_channel"; simple "Out_channel"]
   @ before v (5,0) (List.map simple ["Stream";"Genlex"])
-  @ after v (5,0) [semaphore; effect; domain; simple "Condition"; simple "Mutex"]
+  @ after v (5,0) [semaphore; effekt; domain; simple "Condition"; simple "Mutex"]
   @ after v (5,1) [chain "Type" ["Id"]]
   @ complex v
   @ simples
diff --git a/lib/ast_converter.mlp b/lib/ast_converter.mlp
index 96c04cc..7981b95 100644
--- a/lib/ast_converter.mlp
+++ b/lib/ast_converter.mlp
@@ -469,6 +469,10 @@ and pattern pat =
 | Ppat_open (m,p) (* M.(P) *) ->
     Pattern.open_ (with_loc m.loc @@ H.npath m) @@ pattern p
 #end
+# 5.3, oo
+| Ppat_effect (e, k) (* effect P, k *) ->
+   Pattern.( pattern e ++ pattern k)
+#end
 
 and type_declaration td: M2l.Annot.t  =
   Annot.union_map (fun (_,t,_) -> core_type t) td.ptype_cstrs