diff --git a/lib/excoveralls/poster.ex b/lib/excoveralls/poster.ex
index fba50f3..fca0a6e 100644
--- a/lib/excoveralls/poster.ex
+++ b/lib/excoveralls/poster.ex
@@ -43,6 +43,10 @@ defmodule ExCoveralls.Poster do
       {:ok, status_code, _, _} when status_code in 200..299 ->
         {:ok, "Successfully uploaded the report to '#{endpoint}'."}
 
+      {:ok, 500 = _status_code, _, _client} ->
+        {:ok, "API endpoint `#{endpoint}` is not available and return internal server error! Ignoring upload"}
+      {:ok, 405 = _status_code, _, _client} ->
+        {:ok, "API endpoint `#{endpoint}` is not available due to maintenance! Ignoring upload"}
       {:ok, status_code, _, client} ->
         {:ok, body} = :hackney.body(client)
 
diff --git a/test/poster_test.exs b/test/poster_test.exs
index a5e0791..ad3952e 100644
--- a/test/poster_test.exs
+++ b/test/poster_test.exs
@@ -21,4 +21,16 @@ defmodule PosterTest do
       assert ExCoveralls.Poster.execute("json") == :ok
     end) =~ ~r/timeout/
   end
+
+  test_with_mock "post json fails due internal server error", :hackney, [request: fn(_, _, _, _, _) -> {:ok, 500, "", ""} end] do
+    assert capture_io(fn ->
+      assert ExCoveralls.Poster.execute("json") == :ok
+    end) =~ ~r/internal server error/
+  end
+
+  test_with_mock "post json fails due to maintenance", :hackney, [request: fn(_, _, _, _, _) -> {:ok, 405, "", ""} end] do
+    assert capture_io(fn ->
+      assert ExCoveralls.Poster.execute("json") == :ok
+    end) =~ ~r/maintenance/
+  end
 end