diff --git a/README.adoc b/README.adoc
index 8ae42eb..1c663e5 100644
--- a/README.adoc
+++ b/README.adoc
@@ -396,7 +396,7 @@ strings and you can use unsupported fields in an `Entity` by converting it to
 
 * [x] Account
 * [x] Application
-* [ ] Attachment
+* [x] Attachment
 * [ ] Card
 * [ ] Context
 * [ ] Conversation
diff --git a/tests/entities/test_attachment.cpp b/tests/entities/test_attachment.cpp
new file mode 100644
index 0000000..a5dfb8b
--- /dev/null
+++ b/tests/entities/test_attachment.cpp
@@ -0,0 +1,110 @@
+/*  This file is part of mastodon-cpp.
+ *  Copyright © 2019 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <exception>
+#include <string>
+#include <catch.hpp>
+#include "easy/entities/attachment.hpp"
+
+using std::string;
+
+using namespace Mastodon;
+
+SCENARIO ("Easy::Attachment works as intended", "[entity]")
+{
+    GIVEN ("An Easy::Attachment object")
+    {
+        Easy::Attachment att;
+        bool exception = false;
+
+        WHEN ("It is initialized with valid attachment data")
+        {
+            const string url
+                = "https://example.com/media/e5432f56630c1e38080d135295e33aeb"
+                "ee21e28a46c2172dc010f5e06fe0bd6a.png?name=tux.png";
+            const string data =
+                "{\"description\" : \"tux.png\","
+                "\"id\" : \"2127742613\","
+                "\"pleroma\" : {"
+                    "\"mime_type\" : \"image/png\"},"
+                "\"preview_url\" : \"" + url + "\","
+                "\"remote_url\" : \"" + url + "\","
+                "\"text_url\" : \"" + url + "\","
+                "\"type\" : \"image\","
+                "\"url\" :"
+                  "\"https://example.com/media/e5432f56630c1e38080d135295e33aeb"
+                  "ee21e28a46c2172dc010f5e06fe0bd6a.png?name=tux.png\"}";
+
+            try
+            {
+                att.from_string(data);
+            }
+            catch (const std::exception &e)
+            {
+                exception = true;
+            }
+
+            THEN ("No exception is thrown")
+                AND_THEN ("Attachment is valid")
+                AND_THEN ("The attributes are set to the right values")
+            {
+                REQUIRE_FALSE(exception);
+                REQUIRE(att.valid());
+
+                REQUIRE(att.id() == "2127742613");
+                REQUIRE(att.type() == Easy::attachment_type::Image);
+                REQUIRE(att.url() == url);
+                REQUIRE(att.remote_url() == url);
+                REQUIRE(att.preview_url() == url);
+                REQUIRE(att.meta().valid());
+                REQUIRE(att.description() == "tux.png");
+                REQUIRE(att.meta().width() == 0);
+                REQUIRE(att.meta().width_small() == 0);
+                REQUIRE(att.meta().height() == 0);
+                REQUIRE(att.meta().height_small() == 0);
+                REQUIRE(att.meta().size() == "");
+                REQUIRE(att.meta().size_small() == "");
+                REQUIRE(att.meta().aspect() == 0.0);
+                REQUIRE(att.meta().aspect_small() == 0.0);
+                REQUIRE(att.meta().frame_rate() == 0.0);
+                REQUIRE(att.meta().duration()
+                        == std::chrono::duration<double>(0.0));
+                REQUIRE(att.meta().bitrate() == 0);
+            }
+        }
+
+        WHEN ("It is initialized with an empty string")
+        {
+            try
+            {
+                att.from_string("");
+            }
+            catch (const std::exception &e)
+            {
+                exception = true;
+            }
+
+            THEN ("No exception is thrown")
+                AND_THEN ("It is not valid")
+                AND_THEN ("id is empty")
+            {
+                REQUIRE_FALSE(exception);
+                REQUIRE_FALSE(att.valid());
+                REQUIRE(att.id() == "");
+            }
+        }
+    }
+}