diff --git a/README.md b/README.md
index 771a6c0..0d58c31 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ npm run build # Build component library with rollup.
 ``` 
 
 ### Design Tokens
-CSS variables are declared in `src/tokens.css`. Dark mode is enabled by the presence of the attribute `data-theme` higher up in the tree.
+CSS variables are declared in `src/tokens.css`. Dark mode is enabled by the presence of the attribute `data-theme="dark"` higher up in the tree.