diff --git a/lib/pleroma/upload.ex b/lib/pleroma/upload.ex
index 91a5db8c5..1a97e9fde 100644
--- a/lib/pleroma/upload.ex
+++ b/lib/pleroma/upload.ex
@@ -85,6 +85,10 @@ defmodule Pleroma.Upload do
     end
   end
 
+  def char_unescaped?(char) do
+    URI.char_unreserved?(char) or char == ?/
+  end
+
   defp get_opts(opts) do
     {size_limit, activity_type} =
       case Keyword.get(opts, :type) do
@@ -218,9 +222,7 @@ defmodule Pleroma.Upload do
   defp url_from_spec(base_url, {:file, path}) do
     path =
       path
-      |> URI.encode()
-      |> String.replace("?", "%3F")
-      |> String.replace(":", "%3A")
+      |> URI.encode(&char_unescaped?/1)
 
     [base_url, "media", path]
     |> Path.join()
diff --git a/test/upload_test.exs b/test/upload_test.exs
index b2d9eca38..bdda01b3f 100644
--- a/test/upload_test.exs
+++ b/test/upload_test.exs
@@ -153,19 +153,20 @@ defmodule Pleroma.UploadTest do
       assert Path.basename(attachment_url["href"]) == "an%E2%80%A6%20image.jpg"
     end
 
-    test "replaces : (colon) and ? (question-mark) to %3A and %3F (respectively)" do
+    test "escapes reserved uri characters" do
       File.cp!("test/fixtures/image.jpg", "test/fixtures/image_tmp.jpg")
 
       file = %Plug.Upload{
         content_type: "image/jpg",
         path: Path.absname("test/fixtures/image_tmp.jpg"),
-        filename: "is:an?image.jpg"
+        filename: ":?#[]@!$&\\'()*+,;=.jpg"
       }
 
       {:ok, data} = Upload.store(file)
       [attachment_url | _] = data["url"]
 
-      assert Path.basename(attachment_url["href"]) == "is%3Aan%3Fimage.jpg"
+      assert Path.basename(attachment_url["href"]) ==
+               "%3A%3F%23%5B%5D%40%21%24%26%5C%27%28%29%2A%2B%2C%3B%3D.jpg"
     end
   end
 end