diff --git a/app/assets/stylesheets/framework/typography.scss b/app/assets/stylesheets/framework/typography.scss
index db5e2c51fe7704fff0c8209a99063413bc299c24..c241816788b4f9ee361fde5c5a5f9a4601dfbcbc 100644
--- a/app/assets/stylesheets/framework/typography.scss
+++ b/app/assets/stylesheets/framework/typography.scss
@@ -306,6 +306,11 @@ a > code {
  * Textareas intended for GFM
  *
  */
+textarea.js-gfm-input {
+  font-family: $monospace_font;
+  font-size: 13px;
+}
+
 .strikethrough {
   text-decoration: line-through;
 }
diff --git a/changelogs/unreleased/26236-monospace-gfm.yml b/changelogs/unreleased/26236-monospace-gfm.yml
new file mode 100644
index 0000000000000000000000000000000000000000..c44f3d4d3dc44f96776641109ec1a281417476dc
--- /dev/null
+++ b/changelogs/unreleased/26236-monospace-gfm.yml
@@ -0,0 +1,4 @@
+---
+title: Change gfm textarea to use monospace font
+merge_request:
+author: