diff --git a/lib/error.ml b/lib/error.ml
index adab803..ce67da5 100644
--- a/lib/error.ml
+++ b/lib/error.ml
@@ -50,14 +50,14 @@ let print_error (e : lox_error) =
       assert (num_errors <> 0);
       Printf.fprintf stderr "found %d %s:\n" num_errors
         (if num_errors = 1 then "LexerError" else "LexerErrors");
-      List.iter (fun e -> LexerError.show e |> Printf.fprintf stderr "%s\n") es
+      List.iter (fun e -> LexerError.show e |> prerr_endline) es
   | ParserError es ->
       let num_errors = List.length es in
       assert (num_errors <> 0);
       Printf.fprintf stderr "found %d %s:\n" num_errors
         (if num_errors = 1 then "ParserError" else "ParserErrors");
-      List.iter (fun e -> ParserError.show e |> Printf.fprintf stderr "%s\n") es
-  | RuntimeError e -> RuntimeError.show e |> Printf.fprintf stderr "%s\n"
+      List.iter (fun e -> ParserError.show e |> prerr_endline) es
+  | RuntimeError e -> RuntimeError.show e |> prerr_endline
 
 let of_lexer_error e = Result.map_error (fun e -> LexerError e) e
 let of_parser_error e = Result.map_error (fun e -> ParserError e) e
diff --git a/lib/lox.ml b/lib/lox.ml
index 5a43f1e..e462358 100644
--- a/lib/lox.ml
+++ b/lib/lox.ml
@@ -16,13 +16,13 @@ let run ?(env : Environment.environment option) ?(debug = false) (source : strin
   let () =
     if debug then
       let print_tokens () =
-        Printf.fprintf stderr "--- Tokens ---\n";
+        prerr_endline "--- Tokens ---";
         let f token = Printf.fprintf stderr "%s " (Lexer.show_token token) in
         Printf.fprintf stderr "Got %d tokens\n" (List.length tokens);
         List.iter f tokens;
-        Printf.fprintf stderr "\n";
-        Printf.fprintf stderr "--------------\n";
-        Printf.fprintf stderr "\n"
+        prerr_newline ();
+        prerr_endline "--------------";
+        prerr_newline ()
       in
       print_tokens ()
     else ()
@@ -31,11 +31,11 @@ let run ?(env : Environment.environment option) ?(debug = false) (source : strin
   let () =
     if debug then
       let print_statements () =
-        Printf.fprintf stderr "--- Statements ---\n";
-        let f (stmt : Stmt.stmt_node) = Printf.fprintf stderr "%s\n" (Stmt.show_stmt stmt.stmt) in
+        prerr_endline "--- Statements ---";
+        let f (stmt : Stmt.stmt_node) = prerr_endline (Stmt.show_stmt stmt.stmt) in
         List.iter f stmts;
-        Printf.fprintf stderr "------------------\n";
-        Printf.fprintf stderr "\n"
+        prerr_endline "------------------";
+        prerr_newline ()
       in
       print_statements ()
     else ()