diff --git a/README.md b/README.md
index 2fb2d93..bff71e1 100644
--- a/README.md
+++ b/README.md
@@ -232,6 +232,7 @@ It's possible to configure the test run via some environment variables:
 
 ### Master
 
+- Fix adding non-image ressources (<https://github.com/marph91/joppy/issues/24>).
 - Cast `markup_language` to an appropriate enum type.
 - Add changelog.
 
diff --git a/joppy/api.py b/joppy/api.py
index 5f7b99d..fa9f524 100644
--- a/joppy/api.py
+++ b/joppy/api.py
@@ -334,8 +334,14 @@ def add_tag_to_note(self, tag_id: str, note_id: str) -> None:
     def add_resource_to_note(self, resource_id: str, note_id: str) -> None:
         """Add a resource to a given note."""
         note = self.get_note(id_=note_id, fields="body")
-        resource = self.get_resource(id_=resource_id, fields="title")
-        body_with_attachment = f"{note.body}\n![{resource.title}](:/{resource_id})"
+        resource = self.get_resource(id_=resource_id, fields="title,mime")
+        # TODO: Use "assertIsNotNone()" when
+        # https://github.com/python/mypy/issues/5528 is resolved.
+        assert resource.mime is not None
+        image_prefix = "!" if resource.mime.startswith("image/") else ""
+        body_with_attachment = (
+            f"{note.body}\n{image_prefix}[{resource.title}](:/{resource_id})"
+        )
         self.modify_note(note_id, body=body_with_attachment)
 
     def delete_all_notes(self) -> None:
diff --git a/test/test_api.py b/test/test_api.py
index eb858f6..9751463 100644
--- a/test/test_api.py
+++ b/test/test_api.py
@@ -410,19 +410,28 @@ def test_add(self, filename):
     def test_add_to_note(self, filename):
         """Add a resource to an existing note."""
         self.api.add_notebook()
-        note_id = self.api.add_note()
-        resource_id = self.api.add_resource(filename=filename)
-        self.api.add_resource_to_note(resource_id=resource_id, note_id=note_id)
-
-        # Verify the resource is attached to the note.
-        resources = self.api.get_resources(note_id=note_id).items
-        self.assertEqual(len(resources), 1)
-        self.assertEqual(resources[0].id, resource_id)
-
-        # TODO: Seems to be not working.
-        # notes = self.api.get_notes(resource_id=resource_id)["items"]
-        # self.assertEqual(len(notes), 1)
-        # self.assertEqual(notes[0]["id"], note_id)
+        for file_ in ["test/grant_authorization_button.png", filename]:
+            with self.subTest(file_=file_):
+                note_id = self.api.add_note()
+                resource_id = self.api.add_resource(filename=file_)
+                self.api.add_resource_to_note(resource_id=resource_id, note_id=note_id)
+
+                # Verify the resource is attached to the note.
+                resources = self.api.get_resources(
+                    note_id=note_id, fields="id,mime"
+                ).items
+                self.assertEqual(len(resources), 1)
+                self.assertEqual(resources[0].id, resource_id)
+
+                # Verify the markdown is correct (prefix "!" for images).
+                note = self.api.get_note(id_=note_id, fields="body")
+                # TODO: Use "assertIsNotNone()" when
+                # https://github.com/python/mypy/issues/5528 is resolved.
+                assert resources[0].mime is not None
+                image_prefix = "!" if resources[0].mime.startswith("image/") else ""
+                self.assertEqual(
+                    f"\n{image_prefix}[{file_}](:/{resource_id})", note.body
+                )
 
     @with_resource
     def test_delete(self, filename):