diff --git a/src/libraries/monads/composition.ml b/src/libraries/monads/composition.ml
index 0364320faffc7643d507c6a4ee6030f826eb544a..06a2eb82149151d1f5aaa5a44ec3b6819d973f85 100644
--- a/src/libraries/monads/composition.ml
+++ b/src/libraries/monads/composition.ml
@@ -29,20 +29,20 @@ module Make
     (Int : Monad.S)
     (Ext : Monad.S)
     (X : Axiom with type 'a interior = 'a Int.t and type 'a exterior = 'a Ext.t)
-= Monad.Make_based_on_map (struct
+  = Monad.Make_based_on_map (struct
     type 'a t = 'a Int.t Ext.t
     let return  x = Ext.return (Int.return x)
     let map   f m = Ext.map (Int.map f) m
     let flatten m = Ext.map X.swap m |> Ext.flatten |> Ext.map Int.flatten
-end)
+  end)
 
 module Make_with_product
     (Int : Monad.S_with_product) (Ext : Monad.S_with_product)
     (X : Axiom with type 'a interior = 'a Int.t and type 'a exterior = 'a Ext.t)
-= Monad.Make_based_on_map_with_product (struct
+  = Monad.Make_based_on_map_with_product (struct
     type 'a t = 'a Int.t Ext.t
     let return  x = Ext.return (Int.return x)
     let map   f m = Ext.map (Int.map f) m
     let flatten m = Ext.map X.swap m |> Ext.flatten |> Ext.map Int.flatten
     let product l r = Ext.product l r |> Ext.map (fun (l, r) -> Int.product l r)
-end)
+  end)
diff --git a/src/libraries/monads/composition.mli b/src/libraries/monads/composition.mli
index 33afc243e6f557372aab31cb03cb68d2587827c1..3c99b987cd5c0e772df05ca0922e926f5bd4256e 100644
--- a/src/libraries/monads/composition.mli
+++ b/src/libraries/monads/composition.mli
@@ -29,10 +29,10 @@ module Make
     (Int : Monad.S)
     (Ext : Monad.S)
     (_ : Axiom with type 'a interior = 'a Int.t and type 'a exterior = 'a Ext.t)
-: Monad.S with type 'a t = 'a Int.t Ext.t
+  : Monad.S with type 'a t = 'a Int.t Ext.t
 
 module Make_with_product
     (Int : Monad.S_with_product)
     (Ext : Monad.S_with_product)
     (_ : Axiom with type 'a interior = 'a Int.t and type 'a exterior = 'a Ext.t)
-: Monad.S_with_product with type 'a t = 'a Int.t Ext.t
+  : Monad.S_with_product with type 'a t = 'a Int.t Ext.t