diff --git a/src/core/CCFormat.ml b/src/core/CCFormat.ml
index 0af423c3..f20ae774 100644
--- a/src/core/CCFormat.ml
+++ b/src/core/CCFormat.ml
@@ -134,6 +134,7 @@ let _with_file_out filename f =
   begin try
     let x = f fmt in
     Format.pp_print_flush fmt ();
+    close_out oc;
     x
   with e ->
     Format.pp_print_flush fmt ();
diff --git a/src/core/CCPrint.ml b/src/core/CCPrint.ml
index 4b936a7e..8f8ba7a5 100644
--- a/src/core/CCPrint.ml
+++ b/src/core/CCPrint.ml
@@ -141,6 +141,7 @@ let _with_file_out filename f =
   let oc = open_out filename in
   begin try
     let x = f oc in
+    close_out oc;
     x
   with e ->
     close_out_noerr oc;
@@ -148,7 +149,7 @@ let _with_file_out filename f =
   end
 
 let to_file filename format =
-  _with_file_out filename (fun oc -> kfprintf (fun _ -> close_out oc) oc format)
+  _with_file_out filename (fun oc -> fprintf oc format)
 
 (** {2 Monadic IO} *)