diff --git a/Cargo.toml b/Cargo.toml
index bbdc1de..14d7733 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "bipack_ru"
-version = "0.4.3"
+version = "0.4.4"
 edition = "2021"
 license = "Apache-2.0"
 description = "binary size-effective format used in Divan smart contracts, wasm bindings, network protocols, etc."
diff --git a/src/de.rs b/src/de.rs
index ff88dbb..d02a7de 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -269,7 +269,7 @@ mod tests {
     use crate::de::from_bytes;
     use crate::error::Result;
     use crate::ser::{to_buffer, to_bytes};
-    use crate::tools::{to_dump};
+    use crate::tools::{to_dump, ToDump};
 
     #[test]
     fn test_ints() -> Result<()> {
@@ -434,4 +434,11 @@ mod tests {
         assert_eq!(7, packed.len());
     }
 
+    #[test]
+    fn test_str() {
+        let src = "hello";
+        let x = to_bytes(src);
+        println!("{}", x.unwrap().to_dump());
+    }
+
 }
\ No newline at end of file
diff --git a/src/ser.rs b/src/ser.rs
index 80f058d..1a637cd 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -11,7 +11,7 @@ pub struct Serializer<S: BipackSink> {
 }
 
 pub fn to_bytes<T>(value: &T) -> Result<Vec<u8>>
-    where T: Serialize,
+    where T: Serialize + ?Sized,
 {
     let mut serializer = Serializer { output: Vec::new() };
     value.serialize(&mut serializer)?;