diff --git a/src/os/example_test.go b/src/os/example_test.go
index 07f9c76959..d10bab4e1b 100644
--- a/src/os/example_test.go
+++ b/src/os/example_test.go
@@ -21,6 +21,20 @@ func ExampleOpenFile() {
 	}
 }
 
+func ExampleOpenFile_append() {
+	// If the file doesn't exist, create it, or append to the file
+	f, err := os.OpenFile("access.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if _, err := f.Write([]byte("appended some data\n")); err != nil {
+		log.Fatal(err)
+	}
+	if err := f.Close(); err != nil {
+		log.Fatal(err)
+	}
+}
+
 func ExampleChmod() {
 	if err := os.Chmod("some-filename", 0644); err != nil {
 		log.Fatal(err)