diff --git a/bench/vendored/ppx_sexp_conv.v0.15.1/expander/conversion.ml b/bench/vendored/ppx_sexp_conv.v0.15.1/expander/conversion.ml
index a02385f6..08c0b304 100644
--- a/bench/vendored/ppx_sexp_conv.v0.15.1/expander/conversion.ml
+++ b/bench/vendored/ppx_sexp_conv.v0.15.1/expander/conversion.ml
@@ -49,7 +49,7 @@ module Lambda = struct
   let maybe_apply_generic ~loc ~binds maybe_arg cases =
     let expr =
       match maybe_arg with
-      | None -> pexp_function ~loc cases
+      | None -> pexp_function_cases ~loc cases
       | Some arg -> pexp_match ~loc arg cases
     in
     with_let ~loc ~binds expr
diff --git a/bench/vendored/ppx_sexp_conv.v0.15.1/expander/expand_of_sexp.ml b/bench/vendored/ppx_sexp_conv.v0.15.1/expander/expand_of_sexp.ml
index 84d2851f..2da07093 100644
--- a/bench/vendored/ppx_sexp_conv.v0.15.1/expander/expand_of_sexp.ml
+++ b/bench/vendored/ppx_sexp_conv.v0.15.1/expander/expand_of_sexp.ml
@@ -842,7 +842,7 @@ module Str_generate_of_sexp = struct
       [%expr
         let rec [%p Fresh_name.pattern fresh_iter] =
           [%e
-            pexp_function
+            pexp_function_cases
               ~loc
               [ [%pat?
                        Sexplib0.Sexp.List
diff --git a/src/ast_builder.ml b/src/ast_builder.ml
index 04c3eeb0..459270e8 100644
--- a/src/ast_builder.ml
+++ b/src/ast_builder.ml
@@ -43,7 +43,7 @@ module Default = struct
       pexp_desc = Pexp_function ([ case ], None, Pfunction_body e);
     }
 
-  let pexp_function ~loc cases =
+  let pexp_function_cases ~loc cases =
     {
       pexp_loc_stack = [];
       pexp_attributes = [];
@@ -51,6 +51,8 @@ module Default = struct
       pexp_desc = Pexp_function ([], None, Pfunction_cases (cases, loc, []));
     }
 
+  let pexp_function ~loc cases = pexp_function_cases ~loc cases
+
   let value_binding ~loc ~pat ~expr =
     value_binding ~loc ~pat ~expr ~constraint_:None
 
diff --git a/src/ast_builder.mli b/src/ast_builder.mli
index 461f1cc7..e2190eac 100644
--- a/src/ast_builder.mli
+++ b/src/ast_builder.mli
@@ -64,6 +64,15 @@ module Default : sig
     loc:location -> longident loc -> pattern option -> pattern
 
   val pexp_function : loc:location -> Import.cases -> expression
+  [@@ocaml.deprecated "use pexp_function_cases instead."]
+  (** @deprecated
+        This function will be used to construct a {! Parsetree.Pexp_function }
+        in the next release, to retain its current functionality migrate to
+        {! pexp_function_cases}. *)
+
+  val pexp_function_cases : loc:location -> Import.cases -> expression
+  (** [pexp_function_cases] builds an expression in the shape
+      [function C1 -> E1 | ...]. *)
 
   val constructor_declaration :
     loc:location ->