diff --git a/site/content/docs/5.0/content/reboot.md b/site/content/docs/5.0/content/reboot.md
index 4613a7a119..6529e5ef20 100644
--- a/site/content/docs/5.0/content/reboot.md
+++ b/site/content/docs/5.0/content/reboot.md
@@ -33,6 +33,8 @@ Bootstrap utilizes a "native font stack" or "system font stack" for optimum text
 
 ```scss
 $font-family-sans-serif:
+  // Cross-platform generic font family (default user interface font)
+  system-ui,
   // Safari for macOS and iOS (San Francisco)
   -apple-system,
   // Chrome < 56 for macOS (San Francisco)
diff --git a/site/content/docs/5.0/getting-started/rtl.md b/site/content/docs/5.0/getting-started/rtl.md
index aeaf8c8c3e..cd209298b4 100644
--- a/site/content/docs/5.0/getting-started/rtl.md
+++ b/site/content/docs/5.0/getting-started/rtl.md
@@ -116,6 +116,8 @@ For example, to switch from `Helvetica Neue Webfont` for LTR to `Helvetica Neue
 ```scss
 $font-family-sans-serif:
   Helvetica Neue #{"/* rtl:insert:Arabic */"},
+  // Cross-platform generic font family (default user interface font)
+  system-ui,
   // Safari for macOS and iOS (San Francisco)
   -apple-system,
   // Chrome < 56 for macOS (San Francisco)