diff --git a/caching_tag.go b/caching_tag.go
index b7ae850..47725da 100644
--- a/caching_tag.go
+++ b/caching_tag.go
@@ -118,9 +118,13 @@ func (c *cachingTagVisitor) collectTypeKeyTags(path []string, data interface{},
 			c.collectTypeKeyTags(path, item, typeName)
 		}
 	case map[string]interface{}:
-		c.addTagForTypeKey(at, v[at], typeName)
+		if v[at] != nil {
+			c.addTagForTypeKey(at, v[at], typeName)
+		}
 	default:
-		c.Walker.StopWithInternalErr(fmt.Errorf("invalid data type expected map or array map but got %T", v))
+		if v != nil {
+			c.Walker.StopWithInternalErr(fmt.Errorf("invalid data type expected map or array map but got %T", v))
+		}
 	}
 }