diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 64c35660778..116ce615d8c 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -529,13 +529,15 @@ function preLoadCss(cssUrl) {
                 }
                 const link = document.createElement("a");
                 link.href = path;
-                if (path === current_page) {
-                    link.className = "current";
-                }
                 link.textContent = name;
                 const li = document.createElement("li");
                 li.appendChild(link);
                 ul.appendChild(li);
+                // Don't "optimize" this to just use `path`.
+                // We want the browser to normalize this into an absolute URL.
+                if (link.href === current_page) {
+                    li.classList.add("current");
+                }
             }
             sidebar.appendChild(h3);
             sidebar.appendChild(ul);
diff --git a/tests/rustdoc-gui/sidebar.goml b/tests/rustdoc-gui/sidebar.goml
index 56453517a55..e499c159c6c 100644
--- a/tests/rustdoc-gui/sidebar.goml
+++ b/tests/rustdoc-gui/sidebar.goml
@@ -72,6 +72,7 @@ click: "#structs + .item-table .item-name > a"
 assert-count: (".sidebar .sidebar-crate", 1)
 assert-count: (".sidebar .location", 1)
 assert-count: (".sidebar h2", 3)
+assert-text: (".sidebar-elems ul.block > li.current > a", "Foo")
 // We check that there is no crate listed outside of the top level.
 assert-false: ".sidebar-elems > .crate"
 
@@ -110,6 +111,7 @@ click: "#functions + .item-table .item-name > a"
 assert-text: (".sidebar > .sidebar-crate > h2 > a", "lib2")
 assert-count: (".sidebar .location", 0)
 assert-count: (".sidebar h2", 1)
+assert-text: (".sidebar-elems ul.block > li.current > a", "foobar")
 // We check that we don't have the crate list.
 assert-false: ".sidebar-elems > .crate"
 
@@ -118,6 +120,7 @@ assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .sidebar-crate > h2 > a", "lib2")
 assert-text: (".sidebar > .location", "Module module")
 assert-count: (".sidebar .location", 1)
+assert-text: (".sidebar-elems ul.block > li.current > a", "module")
 // Module page requires three headings:
 //   - Presistent crate branding (name and version)
 //   - Module name, followed by TOC for module headings
@@ -138,6 +141,7 @@ assert-text: (".sidebar > .sidebar-elems > h2", "In lib2::module::sub_module")
 assert-property: (".sidebar > .sidebar-elems > h2 > a", {
     "href": "/module/sub_module/index.html",
 }, ENDS_WITH)
+assert-text: (".sidebar-elems ul.block > li.current > a", "sub_sub_module")
 // We check that we don't have the crate list.
 assert-false: ".sidebar-elems .crate"
 assert-text: (".sidebar-elems > section ul > li:nth-child(1)", "Functions")