diff --git a/src/proto_alpha/lib_protocol/src/delegate_services.ml b/src/proto_alpha/lib_protocol/src/delegate_services.ml
index 2b132a144..fb748a760 100644
--- a/src/proto_alpha/lib_protocol/src/delegate_services.ml
+++ b/src/proto_alpha/lib_protocol/src/delegate_services.ml
@@ -50,7 +50,7 @@ module Baker = struct
     let rights_for_level =
       RPC_service.post_service
         ~description:
-          "List delegate allowed to bake for a given level, \
+          "List delegates allowed to bake for a given level, \
            ordered by priority."
         ~query: RPC_query.empty
         ~input: (obj1 (opt "max_priority" int31))
diff --git a/src/proto_alpha/lib_protocol/src/qty_repr.ml b/src/proto_alpha/lib_protocol/src/qty_repr.ml
index d699476d8..2b381c0de 100644
--- a/src/proto_alpha/lib_protocol/src/qty_repr.ml
+++ b/src/proto_alpha/lib_protocol/src/qty_repr.ml
@@ -78,7 +78,7 @@ module Make (T: QTY) : S = struct
   let one_mutez = 1L
   let one_cent = Int64.mul one_mutez 10_000L
   let fifty_cents = Int64.mul one_cent 50L
-  (* 1 tez = 100 cents = 10_000_000 mutez *)
+  (* 1 tez = 100 cents = 1_000_000 mutez *)
   let one = Int64.mul one_cent 100L
   let id = T.id
 
@@ -159,12 +159,12 @@ module Make (T: QTY) : S = struct
     then Some (Int64.sub t1 t2)
     else None
 
-  let (-?) t1 t2 =
+  let ( -? ) t1 t2 =
     match t1 - t2 with
     | None -> error (Subtraction_underflow (t1, t2))
     | Some v -> ok v
 
-  let (+?) t1 t2 =
+  let ( +? ) t1 t2 =
     let t = Int64.add t1 t2 in
     if t < t1
     then error (Addition_overflow (t1, t2))
diff --git a/src/proto_alpha/lib_protocol/src/roll_storage.mli b/src/proto_alpha/lib_protocol/src/roll_storage.mli
index 9f25a4cc2..6de338a1c 100644
--- a/src/proto_alpha/lib_protocol/src/roll_storage.mli
+++ b/src/proto_alpha/lib_protocol/src/roll_storage.mli
@@ -12,7 +12,7 @@
    Basic roll manipulation.
 
    If storage related to roll (a.k.a. `Storage.Roll`) are not used
-   outside this module, this interface enforce the invariant that a
+   outside of this module, this interface enforces the invariant that a
    roll is always either in the limbo list or in a contract list.
 
 *)