diff --git a/src/librustdoc/html/render/write_shared.rs b/src/librustdoc/html/render/write_shared.rs
index 1dd0917699bf4..c1a83ad5820cb 100644
--- a/src/librustdoc/html/render/write_shared.rs
+++ b/src/librustdoc/html/render/write_shared.rs
@@ -268,10 +268,18 @@ pub(super) fn write_shared(
     // Maybe we can change the representation to move this out of main.js?
     write_minify(
         "main.js",
-        static_files::MAIN_JS.replace(
-            "/* INSERT THEMES HERE */",
-            &format!(" = {}", serde_json::to_string(&themes).unwrap()),
-        ),
+        static_files::MAIN_JS
+            .replace(
+                "/* INSERT THEMES HERE */",
+                &format!(" = {}", serde_json::to_string(&themes).unwrap()),
+            )
+            .replace(
+                "/* INSERT RUSTDOC_VERSION HERE */",
+                &format!(
+                    "rustdoc {}",
+                    rustc_interface::util::version_str().unwrap_or("unknown version")
+                ),
+            ),
         cx,
         options,
     )?;
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 2d4bfc62af68e..eb7cc9309f416 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -928,15 +928,24 @@ body.blur > :not(#help) {
 	display: block;
 	margin-right: 0.5rem;
 }
-#help > div > span {
+#help span.top, #help span.bottom {
 	text-align: center;
 	display: block;
-	margin: 10px 0;
 	font-size: 18px;
-	border-bottom: 1px solid #ccc;
+
+}
+#help span.top {
+	text-align: center;
+	display: block;
+	margin: 10px 0;
+	border-bottom: 1px solid;
 	padding-bottom: 4px;
 	margin-bottom: 6px;
 }
+#help span.bottom {
+	clear: both;
+	border-top: 1px solid;
+}
 #help dd { margin: 5px 35px; }
 #help .infos { padding-left: 0; }
 #help h1, #help h2 { margin-top: 0; }
diff --git a/src/librustdoc/html/static/css/themes/ayu.css b/src/librustdoc/html/static/css/themes/ayu.css
index eada8f4a04dae..c79801e830876 100644
--- a/src/librustdoc/html/static/css/themes/ayu.css
+++ b/src/librustdoc/html/static/css/themes/ayu.css
@@ -286,8 +286,8 @@ details.undocumented > summary::before {
 	border-radius: 4px;
 }
 
-#help > div > span {
-	border-bottom-color: #5c6773;
+#help span.bottom, #help span.top {
+	border-color: #5c6773;
 }
 
 .since {
diff --git a/src/librustdoc/html/static/css/themes/dark.css b/src/librustdoc/html/static/css/themes/dark.css
index d9348be6994e2..d2e54070acd68 100644
--- a/src/librustdoc/html/static/css/themes/dark.css
+++ b/src/librustdoc/html/static/css/themes/dark.css
@@ -242,8 +242,8 @@ details.undocumented > summary::before {
 	border-color: #bfbfbf;
 }
 
-#help > div > span {
-	border-bottom-color: #bfbfbf;
+#help span.bottom, #help span.top {
+	border-color: #bfbfbf;
 }
 
 #help dt {
diff --git a/src/librustdoc/html/static/css/themes/light.css b/src/librustdoc/html/static/css/themes/light.css
index 0ffe5929ea593..25d810560c146 100644
--- a/src/librustdoc/html/static/css/themes/light.css
+++ b/src/librustdoc/html/static/css/themes/light.css
@@ -232,8 +232,8 @@ details.undocumented > summary::before {
 	border-color: #bfbfbf;
 }
 
-#help > div > span {
-	border-bottom-color: #bfbfbf;
+#help span.bottom, #help span.top {
+	border-color: #bfbfbf;
 }
 
 .since {
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 1eebd39256459..e396fd9d288db 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -911,6 +911,7 @@ function hideThemeButtonState() {
         });
 
         var book_info = document.createElement("span");
+        book_info.className = "top";
         book_info.innerHTML = "You can find more information in \
             <a href=\"https://doc.rust-lang.org/rustdoc/\">the rustdoc book</a>.";
 
@@ -961,6 +962,14 @@ function hideThemeButtonState() {
         container.appendChild(div_shortcuts);
         container.appendChild(div_infos);
 
+        var rustdoc_version = document.createElement("span");
+        rustdoc_version.className = "bottom";
+        var rustdoc_version_code = document.createElement("code");
+        rustdoc_version_code.innerText = "/* INSERT RUSTDOC_VERSION HERE */";
+        rustdoc_version.appendChild(rustdoc_version_code);
+
+        container.appendChild(rustdoc_version);
+
         popup.appendChild(container);
         insertAfter(popup, searchState.outputElement());
         // So that it's only built once and then it'll do nothing when called!