diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_toggle.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_toggle.rhtml
index b51448a8f7..8710d75b48 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_toggle.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_toggle.rhtml
@@ -1,3 +1,3 @@
 <button id="navigation-toggle" class="navigation-toggle" aria-label="Toggle sidebar" aria-expanded="true" aria-controls="navigation">
-  <span aria-hidden>☰</span>
+  <span aria-hidden>&#9776;</span>
 </button>