diff --git a/ntex-io/Cargo.toml b/ntex-io/Cargo.toml
index 86bb6d72..4c8a1cde 100644
--- a/ntex-io/Cargo.toml
+++ b/ntex-io/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ntex-io"
-version = "0.3.3"
+version = "0.3.4"
 authors = ["ntex contributors <team@ntex.rs>"]
 description = "Utilities for encoding and decoding frames"
 keywords = ["network", "framework", "async", "futures"]
diff --git a/ntex-io/src/ioref.rs b/ntex-io/src/ioref.rs
index 989279ac..b91ab17b 100644
--- a/ntex-io/src/ioref.rs
+++ b/ntex-io/src/ioref.rs
@@ -375,6 +375,7 @@ mod tests {
         assert_eq!(waiter.await, ());
     }
 
+    #[derive(Debug)]
     struct Counter {
         idx: usize,
         in_bytes: Rc<Cell<usize>>,
diff --git a/ntex-io/src/utils.rs b/ntex-io/src/utils.rs
index 0149d3db..dc533ca4 100644
--- a/ntex-io/src/utils.rs
+++ b/ntex-io/src/utils.rs
@@ -130,6 +130,7 @@ mod tests {
         assert_eq!(buf, b"RES".as_ref());
     }
 
+    #[derive(Debug)]
     pub(crate) struct TestFilter;
 
     impl FilterLayer for TestFilter {
diff --git a/ntex/Cargo.toml b/ntex/Cargo.toml
index e18ebec9..b7d45734 100644
--- a/ntex/Cargo.toml
+++ b/ntex/Cargo.toml
@@ -58,7 +58,7 @@ ntex-util = "0.3.2"
 ntex-bytes = "0.1.19"
 ntex-h2 = "0.3.2"
 ntex-rt = "0.4.9"
-ntex-io = "0.3.3"
+ntex-io = "0.3.4"
 ntex-tls = "0.3.1"
 ntex-tokio = { version = "0.3.0", optional = true }
 ntex-glommio = { version = "0.3.0", optional = true }