diff --git a/sqlx-mysql/Cargo.toml b/sqlx-mysql/Cargo.toml
index 81b603d9..433c4a1e 100644
--- a/sqlx-mysql/Cargo.toml
+++ b/sqlx-mysql/Cargo.toml
@@ -42,7 +42,7 @@ base64 = "0.13.0"
 rand = "0.7"
 
 [dev-dependencies]
-sqlx-core = { version = "0.6.0-pre", path = "../sqlx-core", features = ["_mock", "tokio"] }
+sqlx-core = { version = "0.6.0-pre", path = "../sqlx-core", features = ["_mock"] }
 futures-executor = "0.3.8"
 anyhow = "1.0.37"
 tokio = { version = "1.0", features = ["full"] }
@@ -51,4 +51,4 @@ once_cell = "1.5.2"
 [[test]]
 name = "mysql-connection"
 path = "tests/connection.rs"
-required-features = ["async"]
+required-features = ["async", "sqlx-core/tokio"]
diff --git a/sqlx-mysql/src/connection.rs b/sqlx-mysql/src/connection.rs
index 840d7767..4a63c3f0 100644
--- a/sqlx-mysql/src/connection.rs
+++ b/sqlx-mysql/src/connection.rs
@@ -25,6 +25,7 @@ mod ping;
 pub struct MySqlConnection<Rt: Runtime> {
     stream: MySqlStream<Rt>,
     connection_id: u32,
+
     closed: bool,
 
     // the capability flags are used by the client and server to indicate which
@@ -60,6 +61,11 @@ impl<Rt: Runtime> MySqlConnection<Rt> {
                 | Capabilities::DEPRECATE_EOF,
         }
     }
+
+    /// Returns the server-assigned connection identifier associated with this connection.
+    pub fn id(&self) -> u32 {
+        self.connection_id
+    }
 }
 
 impl<Rt: Runtime> Debug for MySqlConnection<Rt> {
diff --git a/sqlx-mysql/src/connection/command.rs b/sqlx-mysql/src/connection/command.rs
index df12891e..4f185047 100644
--- a/sqlx-mysql/src/connection/command.rs
+++ b/sqlx-mysql/src/connection/command.rs
@@ -102,7 +102,11 @@ impl Deref for CommandGuard<'_, QueryCommand> {
     fn deref(&self) -> &Self::Target {
         debug_assert!(!self.ended);
 
-        if let Command::Query(cmd) = &self.queue.0[self.index] { cmd } else { unreachable!() }
+        if let Command::Query(cmd) = &self.queue.0[self.index] {
+            cmd
+        } else {
+            unreachable!()
+        }
     }
 }
 
@@ -110,7 +114,11 @@ impl DerefMut for CommandGuard<'_, QueryCommand> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         debug_assert!(!self.ended);
 
-        if let Command::Query(cmd) = &mut self.queue.0[self.index] { cmd } else { unreachable!() }
+        if let Command::Query(cmd) = &mut self.queue.0[self.index] {
+            cmd
+        } else {
+            unreachable!()
+        }
     }
 }
 
@@ -139,7 +147,11 @@ impl Deref for CommandGuard<'_, PrepareCommand> {
     fn deref(&self) -> &Self::Target {
         debug_assert!(!self.ended);
 
-        if let Command::Prepare(cmd) = &self.queue.0[self.index] { cmd } else { unreachable!() }
+        if let Command::Prepare(cmd) = &self.queue.0[self.index] {
+            cmd
+        } else {
+            unreachable!()
+        }
     }
 }
 
@@ -147,6 +159,10 @@ impl DerefMut for CommandGuard<'_, PrepareCommand> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         debug_assert!(!self.ended);
 
-        if let Command::Prepare(cmd) = &mut self.queue.0[self.index] { cmd } else { unreachable!() }
+        if let Command::Prepare(cmd) = &mut self.queue.0[self.index] {
+            cmd
+        } else {
+            unreachable!()
+        }
     }
 }
diff --git a/sqlx-mysql/src/protocol/auth_response.rs b/sqlx-mysql/src/protocol/auth_response.rs
index e109de2f..b4a10c21 100644
--- a/sqlx-mysql/src/protocol/auth_response.rs
+++ b/sqlx-mysql/src/protocol/auth_response.rs
@@ -5,7 +5,7 @@ use sqlx_core::io::Deserialize;
 use sqlx_core::Result;
 
 use crate::protocol::{AuthSwitch, Capabilities, ResultPacket};
-use crate::{MySqlClientError, MySqlDatabaseError};
+use crate::MySqlClientError;
 
 #[derive(Debug)]
 pub(crate) enum AuthResponse {
diff --git a/sqlx-mysql/src/protocol/auth_switch.rs b/sqlx-mysql/src/protocol/auth_switch.rs
index dee71c2f..1a042c9c 100644
--- a/sqlx-mysql/src/protocol/auth_switch.rs
+++ b/sqlx-mysql/src/protocol/auth_switch.rs
@@ -28,7 +28,7 @@ impl Deserialize<'_> for AuthSwitch {
 
         let plugin_data = buf.chain(Bytes::new());
 
-        let plugin = AuthPlugin::parse(&*name)?;
+        let plugin = <dyn AuthPlugin>::parse(&*name)?;
 
         Ok(Self { plugin, plugin_data })
     }
diff --git a/sqlx-mysql/src/protocol/handshake.rs b/sqlx-mysql/src/protocol/handshake.rs
index 240176ec..25124c80 100644
--- a/sqlx-mysql/src/protocol/handshake.rs
+++ b/sqlx-mysql/src/protocol/handshake.rs
@@ -112,7 +112,7 @@ impl Deserialize<'_> for Handshake {
             status,
             auth_plugin_data: auth_plugin_data_1.chain(auth_plugin_data_2),
             auth_plugin: auth_plugin_name
-                .map(|name| AuthPlugin::parse(&name))
+                .map(|name| <dyn AuthPlugin>::parse(&name))
                 .transpose()?
                 .unwrap_or_else(|| Box::new(NativeAuthPlugin)),
         })
diff --git a/sqlx-mysql/src/protocol/query_response.rs b/sqlx-mysql/src/protocol/query_response.rs
index caa90cb0..c44d234e 100644
--- a/sqlx-mysql/src/protocol/query_response.rs
+++ b/sqlx-mysql/src/protocol/query_response.rs
@@ -4,7 +4,7 @@ use sqlx_core::Result;
 
 use super::{Capabilities, ResultPacket};
 use crate::io::MySqlBufExt;
-use crate::{MySqlClientError, MySqlDatabaseError};
+use crate::MySqlClientError;
 
 /// The query-response packet is a meta-packet that starts with one of:
 ///
diff --git a/sqlx-mysql/src/stream.rs b/sqlx-mysql/src/stream.rs
index e7829e86..04df2176 100644
--- a/sqlx-mysql/src/stream.rs
+++ b/sqlx-mysql/src/stream.rs
@@ -7,7 +7,7 @@ use sqlx_core::net::Stream as NetStream;
 use sqlx_core::{Result, Runtime};
 
 use crate::protocol::{MaybeCommand, Packet, Quit};
-use crate::{MySqlClientError, MySqlDatabaseError};
+use crate::MySqlClientError;
 
 /// Reads and writes packets to and from the MySQL database server.
 ///
diff --git a/x.py b/x.py
index f0187400..01e26091 100755
--- a/x.py
+++ b/x.py
@@ -235,7 +235,7 @@ def run_integration_test(project: str, database: str):
         "-q" if argv.quiet else None,
         "--message-format", "human" if argv.verbose else "short",
         "--manifest-path", f"{project}/Cargo.toml",
-        "--features", "async",
+        "--features", "async,sqlx-core/tokio",
         *unknown,
     ] if x], env=env, cwd=project_dir, comment=f"integration test {project}", tag=tag)