diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index ee94f0baeb9a3..26a64f6cd2245 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -126,6 +126,10 @@ p {
 	margin: 0 0 .6em 0;
 }
 
+summary {
+	outline: none;
+}
+
 code, pre {
 	font-family: "Source Code Pro", Menlo, Monaco, Consolas, "DejaVu Sans Mono", Inconsolata, monospace;
 	white-space: pre-wrap;