diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b3f1532f..1277ce0d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,8 +16,8 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - { rust: stable, os: ubuntu-latest }
-          - { rust: 1.54.0, os: ubuntu-latest }
+#          - { rust: stable, os: ubuntu-latest }
+          - { rust: 1.56.1, os: ubuntu-latest }
     steps:
       - name: Checkout
         uses: actions/checkout@v2
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c683eee1..96150677 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+- Use Rust `2021` edition.
+
 ## [2.10.8] 2021-10-26
 
 - [async-graphql-poem] Bump poem to `1.0.13`. 
diff --git a/README.md b/README.md
index 6954e70f..09a94ec8 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,7 @@
 * [Docs](https://docs.rs/async-graphql)
 * [GitHub repository](https://github.com/async-graphql/async-graphql)
 * [Cargo package](https://crates.io/crates/async-graphql)
-* Minimum supported Rust version: 1.54.0 or later
+* Minimum supported Rust version: 1.56.1 or later
 
 ## Safety
 
diff --git a/derive/src/utils.rs b/derive/src/utils.rs
index dc0dfcbf..394a30d4 100644
--- a/derive/src/utils.rs
+++ b/derive/src/utils.rs
@@ -316,11 +316,11 @@ fn generate_default_value(lit: &Lit) -> GeneratorResult<TokenStream> {
         }
         Lit::Int(value) => {
             let value = value.base10_parse::<i32>()?;
-            Ok(quote!({ ::TryInto::try_into(#value).unwrap() }))
+            Ok(quote!({ ::std::convert::TryInto::try_into(#value).unwrap() }))
         }
         Lit::Float(value) => {
             let value = value.base10_parse::<f64>()?;
-            Ok(quote!({ ::TryInto::try_into(#value) }))
+            Ok(quote!({ ::std::convert::TryInto::try_into(#value) }))
         }
         Lit::Bool(value) => {
             let value = value.value;
diff --git a/examples b/examples
index 1683aac1..b1faa106 160000
--- a/examples
+++ b/examples
@@ -1 +1 @@
-Subproject commit 1683aac1883a6acf27747bf3e22491fa13aa538f
+Subproject commit b1faa1061fb895ba0a325f01a09effea5fad50c8
diff --git a/value/src/lib.rs b/value/src/lib.rs
index 033c5376..bf40e624 100644
--- a/value/src/lib.rs
+++ b/value/src/lib.rs
@@ -10,7 +10,6 @@ mod value_serde;
 mod variables;
 
 use std::borrow::{Borrow, Cow};
-use std::collections::BTreeMap;
 use std::fmt::{self, Display, Formatter, Write};
 use std::ops::Deref;
 use std::sync::Arc;