diff --git a/src/kernel_services/ast_printing/cil_printer.mli b/src/kernel_services/ast_printing/cil_printer.mli
index bca6dd1a6ac74773858c35cb61a7527d5c6693a2..20761da4fbddf55e599663f6ef423fee3e84a15f 100644
--- a/src/kernel_services/ast_printing/cil_printer.mli
+++ b/src/kernel_services/ast_printing/cil_printer.mli
@@ -43,7 +43,7 @@ val register_behavior_extension:
     @plugin development guide
     @deprecated Frama-C+dev
 *)
-[@@ deprecated "Use Acsl_extension.register_behavior instead"]
+[@@ deprecated "Use Acsl_extension.register_behavior (arg: ~printer) instead"]
 
 val register_global_extension:
   string ->
@@ -53,7 +53,7 @@ val register_global_extension:
     @plugin development guide
     @deprecated Frama-C+dev
 *)
-[@@ deprecated "Use Acsl_extension.register_global instead"]
+[@@ deprecated "Use Acsl_extension.register_global (arg: ~printer) instead"]
 
 val register_code_annot_extension:
   string ->
@@ -63,7 +63,7 @@ val register_code_annot_extension:
     @plugin development guide
     @deprecated Frama-C+dev
 *)
-[@@ deprecated "Use Acsl_extension.register_code_annot_<kind> instead"]
+[@@ deprecated "Use Acsl_extension.register_code_annot_<kind> (arg: ~printer) instead"]
 
 val register_loop_annot_extension:
   string ->
@@ -73,7 +73,7 @@ val register_loop_annot_extension:
     @plugin development guide
     @deprecated Frama-C+dev
 *)
-[@@ deprecated "Use Acsl_extension.register_loop_annot instead"]
+[@@ deprecated "Use Acsl_extension.register_loop_annot (arg: ~printer) instead"]
 
 val state: Printer_api.state
 
@@ -90,7 +90,7 @@ val set_extension_handler:
                Format.formatter -> Cil_types.acsl_extension_kind -> unit) ->
   unit
 (** Used to setup a reference related to the handling of ACSL extensions.
-    If your name is not [Acsl_extension], do not call this
+    If your name is not [Acsl_extension], do not call this.
     @since Frama-C+dev
 *)
 
diff --git a/src/kernel_services/ast_queries/cil.mli b/src/kernel_services/ast_queries/cil.mli
index 186a826e2423daa1ce8ef18b968491b4dae8c184..45ed7d8e6a810257090bfe89984685338084b964 100644
--- a/src/kernel_services/ast_queries/cil.mli
+++ b/src/kernel_services/ast_queries/cil.mli
@@ -1731,7 +1731,7 @@ val register_behavior_extension:
   string ->
   (cilVisitor -> acsl_extension_kind -> (acsl_extension_kind) visitAction)
   -> unit
-[@@ deprecated "Use Acsl_extension.register_behavior instead"]
+[@@ deprecated "Use Acsl_extension.register_behavior instead (arg: ~visitor)"]
 
 (**/**)
 class internal_genericCilVisitor: