diff --git a/vendor/src/gopkg.in/yaml.v2/decode.go b/vendor/src/gopkg.in/yaml.v2/decode.go
index e85eb2e..01ec24f 100644
--- a/vendor/src/gopkg.in/yaml.v2/decode.go
+++ b/vendor/src/gopkg.in/yaml.v2/decode.go
@@ -559,9 +559,17 @@ func (d *decoder) mapping(n *node, out reflect.Value) (good bool) {
            if kkind == reflect.Map || kkind == reflect.Slice {
                failf("invalid map key: %#v", k.Interface())
            }
-           e := reflect.New(et).Elem()
-           if d.unmarshal(n.children[i+1], e) {
-               out.SetMapIndex(k, e)
+           e := out.MapIndex(k)
+           if e.IsValid() {
+               // Reuse map entry.
+               e = e.Elem()
+               d.unmarshal(n.children[i+1], e)
+           } else {
+               // Add new map entry.
+               e := reflect.New(et).Elem()
+               if d.unmarshal(n.children[i+1], e) {
+                   out.SetMapIndex(k, e)
+               }
            }
        }
    }