diff --git a/internal/godoc/dochtml/internal/render/linkify_test.go b/internal/godoc/dochtml/internal/render/linkify_test.go
index bbcf5e767..9c8bc83a7 100644
--- a/internal/godoc/dochtml/internal/render/linkify_test.go
+++ b/internal/godoc/dochtml/internal/render/linkify_test.go
@@ -296,6 +296,18 @@ b := 1
 	line comment.
 */
 </pre>
+`,
+		},
+		{
+			"An Output comment must appear at the start of the line.",
+			`_ = true
+// This comment containing "// Output:" is not treated specially.
+`,
+			`
+<pre class="Documentation-exampleCode">
+_ = true
+// This comment containing &#34;// Output:&#34; is not treated specially.
+</pre>
 `,
 		},
 	} {
diff --git a/internal/godoc/dochtml/internal/render/render.go b/internal/godoc/dochtml/internal/render/render.go
index dc133d9fa..157fd9d44 100644
--- a/internal/godoc/dochtml/internal/render/render.go
+++ b/internal/godoc/dochtml/internal/render/render.go
@@ -21,7 +21,8 @@ import (
 
 var (
 	// Regexp for example outputs.
-	exampleOutputRx = regexp.MustCompile(`(?i)//[[:space:]]*(unordered )?output:`)
+	// Keep consistent with outputPrefix in GOROOT/src/go/doc/example.go.
+	exampleOutputRx = regexp.MustCompile(`(?i)^[[:space:]]*//[[:space:]]*(unordered )?output:`)
 )
 
 type Renderer struct {