diff --git a/changelogs/unreleased/features-document-graphicsmagick-source-installation.yml b/changelogs/unreleased/features-document-graphicsmagick-source-installation.yml
new file mode 100644
index 0000000000000000000000000000000000000000..b224cace4bf4d0a0c070c615b6300ddf4c98cd87
--- /dev/null
+++ b/changelogs/unreleased/features-document-graphicsmagick-source-installation.yml
@@ -0,0 +1,5 @@
+---
+title: Document graphicsmagick installation for source installation
+merge_request: 24404
+author: Alexis Reigel
+type: added
diff --git a/doc/install/installation.md b/doc/install/installation.md
index 678c306a484b0ed2d115bf31099a67a8f7de0f59..2eba2cc484755b16e5052135230861da674414cd 100644
--- a/doc/install/installation.md
+++ b/doc/install/installation.md
@@ -117,6 +117,13 @@ sudo make prefix=/usr/local install
 # When editing config/gitlab.yml (Step 5), change the git -> bin_path to /usr/local/bin/git
 ```
 
+For the [Custom Favicon](../customization/favicon.md) to work, graphicsmagick
+needs to be installed.
+
+```sh
+sudo apt-get install -y graphicsmagick
+```
+
 **Note:** In order to receive mail notifications, make sure to install a mail server. By default, Debian is shipped with exim4 but this [has problems](https://gitlab.com/gitlab-org/gitlab-ce/issues/12754) while Ubuntu does not ship with one. The recommended mail server is postfix and you can install it with:
 
 ```sh