diff --git a/ch1-basic/ch1-04-func-method-interface.md b/ch1-basic/ch1-04-func-method-interface.md
index d956885..7578732 100644
--- a/ch1-basic/ch1-04-func-method-interface.md
+++ b/ch1-basic/ch1-04-func-method-interface.md
@@ -63,7 +63,8 @@ func Print(a ...interface{}) {
 
 ```go
 func Find(m map[int]int, key int) (value int, ok bool) {
-	return m[key]
+	value, ok = m[key]
+	return
 }
 ```