diff --git a/Cargo.toml b/Cargo.toml
index 85ed01eb28..a962b5720d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ members = ["crates/*"]
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.67"
+rust-version = "1.69"
 homepage = "https://beta.ruff.rs/docs/"
 documentation = "https://beta.ruff.rs/docs/"
 repository = "https://github.com/charliermarsh/ruff"
diff --git a/crates/ruff/src/noqa.rs b/crates/ruff/src/noqa.rs
index 397054f9ea..7752c55b1f 100644
--- a/crates/ruff/src/noqa.rs
+++ b/crates/ruff/src/noqa.rs
@@ -352,7 +352,7 @@ fn push_codes<I: Display>(str: &mut String, codes: impl Iterator<Item = I>) {
         if !first {
             str.push_str(", ");
         }
-        let _ = write!(str, "{code}");
+        _ = write!(str, "{code}");
         first = false;
     }
 }
diff --git a/crates/ruff_diagnostics/Cargo.toml b/crates/ruff_diagnostics/Cargo.toml
index c24ef1aa81..5565d595a4 100644
--- a/crates/ruff_diagnostics/Cargo.toml
+++ b/crates/ruff_diagnostics/Cargo.toml
@@ -13,4 +13,4 @@ log = { workspace = true }
 ruff_python_ast = { path = "../ruff_python_ast" }
 
 rustpython-parser = { workspace = true }
-serde = { workspace = true, optional = true, default_features = false, features = [] }
+serde = { workspace = true, optional = true, features = [] }
diff --git a/crates/ruff_testing_macros/src/lib.rs b/crates/ruff_testing_macros/src/lib.rs
index 7ed6c5deef..622da40057 100644
--- a/crates/ruff_testing_macros/src/lib.rs
+++ b/crates/ruff_testing_macros/src/lib.rs
@@ -42,7 +42,7 @@ impl Parse for ArgValue {
     fn parse(input: ParseStream) -> syn::Result<Self> {
         let value = if input.peek(syn::token::Bracket) {
             let inner;
-            let _ = bracketed!(inner in input);
+            _ = bracketed!(inner in input);
 
             let values = inner.parse_terminated(
                 |parser| {
diff --git a/crates/ruff_text_size/Cargo.toml b/crates/ruff_text_size/Cargo.toml
index 7c565debe4..357e06f6a2 100644
--- a/crates/ruff_text_size/Cargo.toml
+++ b/crates/ruff_text_size/Cargo.toml
@@ -6,8 +6,7 @@ edition = { workspace = true }
 rust-version = { workspace = true }
 
 [dependencies]
-serde = { workspace = true, optional = true, default_features = false, features = [
-] }
+serde = { workspace = true, optional = true }
 schemars = { workspace = true, optional = true }
 
 [dev-dependencies]
diff --git a/crates/ruff_text_size/tests/constructors.rs b/crates/ruff_text_size/tests/constructors.rs
index 8ee2fde942..d6f88f5042 100644
--- a/crates/ruff_text_size/tests/constructors.rs
+++ b/crates/ruff_text_size/tests/constructors.rs
@@ -12,13 +12,13 @@ impl BadRope<'_> {
 #[test]
 fn main() {
     let x: char = 'c';
-    let _ = TextSize::of(x);
+    _ = TextSize::of(x);
 
     let x: &str = "hello";
-    let _ = TextSize::of(x);
+    _ = TextSize::of(x);
 
     let x: &String = &"hello".into();
-    let _ = TextSize::of(x);
+    _ = TextSize::of(x);
 
-    let _ = BadRope(&[""]).text_len();
+    _ = BadRope(&[""]).text_len();
 }
diff --git a/crates/ruff_text_size/tests/indexing.rs b/crates/ruff_text_size/tests/indexing.rs
index e7205fdeea..b4b4650403 100644
--- a/crates/ruff_text_size/tests/indexing.rs
+++ b/crates/ruff_text_size/tests/indexing.rs
@@ -3,6 +3,6 @@ use ruff_text_size::TextRange;
 #[test]
 fn main() {
     let range = TextRange::default();
-    let _ = &""[range];
-    let _ = &String::new()[range];
+    _ = &""[range];
+    _ = &String::new()[range];
 }
diff --git a/rust-toolchain b/rust-toolchain
index 9ebd7af328..883d7d6539 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.67
+1.69