diff --git a/Cargo.toml b/Cargo.toml
index 2648f15..190b2ca 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bp3d-util"
-version = "2.0.0"
+version = "2.0.1"
 authors = ["Yuri Edward <yuri6037@outlook.com>"]
 edition = "2021"
 description = "OS independant Rust language utilities."
@@ -24,7 +24,7 @@ result = ["extension"]
 path = ["extension"]
 extension = []
 index-map = []
-string = []
+string = ["extension"]
 
 [package.metadata.docs.rs]
 all-features = true