diff --git a/lib/httparrot.ex b/lib/httparrot.ex
index 29d6c07..24027ca 100644
--- a/lib/httparrot.ex
+++ b/lib/httparrot.ex
@@ -54,7 +54,7 @@ defmodule HTTParrot do
   def prettify_json(status, headers, body, req) do
     if JSEX.is_json? body do
       body = JSEX.prettify!(body)
-      headers = List.keystore(headers, "content-length", 0, {"content-length", integer_to_list(String.length(body))})
+      headers = List.keystore(headers, "content-length", 0, {"content-length", Integer.to_char_list(String.length(body))})
       {:ok, req} = :cowboy_req.reply(status, headers, body, req)
     end
     req
diff --git a/lib/httparrot/delayed_handler.ex b/lib/httparrot/delayed_handler.ex
index 3a987bb..a4104a6 100644
--- a/lib/httparrot/delayed_handler.ex
+++ b/lib/httparrot/delayed_handler.ex
@@ -12,7 +12,7 @@ defmodule HTTParrot.DelayedHandler do
   def malformed_request(req, state) do
     {n, req} = :cowboy_req.binding(:n, req)
     try do
-      n = n |> binary_to_integer |> min(10) |> max(0)
+      n = n |> String.to_integer |> min(10) |> max(0)
       {false, req, n}
     rescue
       ArgumentError -> {true, req, state}
diff --git a/lib/httparrot/redirect_handler.ex b/lib/httparrot/redirect_handler.ex
index 4268989..99585ad 100644
--- a/lib/httparrot/redirect_handler.ex
+++ b/lib/httparrot/redirect_handler.ex
@@ -14,7 +14,7 @@ defmodule HTTParrot.RedirectHandler do
   def malformed_request(req, state) do
     {n, req} = :cowboy_req.binding(:n, req)
     try do
-      n = n |> binary_to_integer |> max(1)
+      n = n |> String.to_integer |> max(1)
       {false, req, n}
     rescue
       ArgumentError -> {true, req, state}
diff --git a/lib/httparrot/stream_handler.ex b/lib/httparrot/stream_handler.ex
index d9b516f..6608565 100644
--- a/lib/httparrot/stream_handler.ex
+++ b/lib/httparrot/stream_handler.ex
@@ -18,7 +18,7 @@ defmodule HTTParrot.StreamHandler do
   def malformed_request(req, state) do
     {n, req} = :cowboy_req.binding(:n, req)
     try do
-      n = n |> binary_to_integer |> min(100) |> max(1)
+      n = n |> String.to_integer |> min(100) |> max(1)
       {false, req, n}
     rescue
       ArgumentError -> {true, req, state}