diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8d17f4d6..92afbb0c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -55,7 +55,7 @@ jobs:
       - run: docker compose up -d
       - uses: sfackler/actions/rustup@master
         with:
-          version: 1.62.0
+          version: 1.63.0
       - run: echo "::set-output name=version::$(rustc --version)"
         id: rust-version
       - uses: actions/cache@v1
diff --git a/postgres-derive-test/src/lib.rs b/postgres-derive-test/src/lib.rs
index d1478ac4..f0534f32 100644
--- a/postgres-derive-test/src/lib.rs
+++ b/postgres-derive-test/src/lib.rs
@@ -14,7 +14,7 @@ where
     T: PartialEq + FromSqlOwned + ToSql + Sync,
     S: fmt::Display,
 {
-    for &(ref val, ref repr) in checks.iter() {
+    for (val, repr) in checks.iter() {
         let stmt = conn
             .prepare(&format!("SELECT {}::{}", *repr, sql_type))
             .unwrap();
@@ -38,7 +38,7 @@ pub fn test_type_asymmetric<T, F, S, C>(
     S: fmt::Display,
     C: Fn(&T, &F) -> bool,
 {
-    for &(ref val, ref repr) in checks.iter() {
+    for (val, repr) in checks.iter() {
         let stmt = conn
             .prepare(&format!("SELECT {}::{}", *repr, sql_type))
             .unwrap();
diff --git a/postgres-protocol/src/authentication/sasl.rs b/postgres-protocol/src/authentication/sasl.rs
index 2352a66c..4a77507e 100644
--- a/postgres-protocol/src/authentication/sasl.rs
+++ b/postgres-protocol/src/authentication/sasl.rs
@@ -359,7 +359,7 @@ impl<'a> Parser<'a> {
     }
 
     fn posit_number(&mut self) -> io::Result<u32> {
-        let n = self.take_while(|c| matches!(c, '0'..='9'))?;
+        let n = self.take_while(|c| c.is_ascii_digit())?;
         n.parse()
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidInput, e))
     }