diff --git a/src/bytes/example_test.go b/src/bytes/example_test.go
index 5b7a46058f..4d5cdfa280 100644
--- a/src/bytes/example_test.go
+++ b/src/bytes/example_test.go
@@ -39,6 +39,14 @@ func ExampleBuffer_Grow() {
 	// Output: "64 bytes or fewer"
 }
 
+func ExampleBuffer_Len() {
+	var b bytes.Buffer
+	b.Grow(64)
+	b.Write([]byte("abcde"))
+	fmt.Printf("%d", b.Len())
+	// Output: 5
+}
+
 func ExampleCompare() {
 	// Interpret Compare's result by comparing it to zero.
 	var a, b []byte