diff --git a/README.md b/README.md
index 87bbc8b..ff1368a 100644
--- a/README.md
+++ b/README.md
@@ -606,12 +606,14 @@ type config struct {
 
 var C config
 
-err := Unmarshal(&C)
+err := viper.Unmarshal(&C)
 if err != nil {
 	t.Fatalf("unable to decode into struct, %v", err)
 }
 ```
 
+`mapstructure` is the only supported tag.
+
 ### Marshalling to string
 
 You may need to marhsal all the settings held in viper into a string rather than write them to a file.