diff --git a/netmap/node_info.go b/netmap/node_info.go
index ce3bdb9..63fe047 100644
--- a/netmap/node_info.go
+++ b/netmap/node_info.go
@@ -52,6 +52,7 @@ func (x *NodeInfo) readFromV2(m netmap.NodeInfo, checkFieldPresence bool) error
 		} else if _, ok := mAttr[key]; ok {
 			return fmt.Errorf("duplicate attributes %s", key)
 		}
+		mAttr[key] = struct{}{}
 
 		switch {
 		case key == attrCapacity:
diff --git a/netmap/node_info_test.go b/netmap/node_info_test.go
index bf6e637..65ea0e8 100644
--- a/netmap/node_info_test.go
+++ b/netmap/node_info_test.go
@@ -271,7 +271,6 @@ func TestNodeInfo_Unmarshal(t *testing.T) {
 			fmt.Sprintf("invalid %s attribute", attrCapacity))
 	})
 	t.Run("duplicate attributes", func(t *testing.T) {
-		t.Skip("FIXME")
 		n := goodNodeInfo()
 
 		var a netmap.Attribute