diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 15828c2..ef51dbf 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -12,9 +12,11 @@ env:
 jobs:
   build:
     runs-on: ubuntu-latest
+    env:
+      RUSTFLAGS: "--deny warnings"
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Install wasm32-unknown-unknown target
         run: rustup target add wasm32-unknown-unknown
@@ -53,7 +55,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Install wasm32-unknown-unknown target
         run: rustup target add wasm32-unknown-unknown
@@ -70,7 +72,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       # Tests
       - name: Run tests
@@ -80,8 +82,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       # Typos
       - name: typos-action
         uses: crate-ci/typos@v1.0.4
+      - name: format
+        run: cargo fmt --all -- --check
diff --git a/benches/qr.rs b/benches/qr.rs
index fffd4ec..727f94c 100644
--- a/benches/qr.rs
+++ b/benches/qr.rs
@@ -2,7 +2,7 @@ use std::time::Duration;
 
 use criterion::*;
 
-use fast_qr::{QRBuilder, QRCode};
+use fast_qr::QRBuilder;
 
 fn bench_fastqr_qrcode(c: &mut Criterion) {
     let bytes: &[u8] = b"https://example.com/";
@@ -60,31 +60,5 @@ fn bench_fastqr_qrcode(c: &mut Criterion) {
     }
 }
 
-fn bench_mask(c: &mut Criterion) {
-    let mut group = c.benchmark_group("mask");
-    group.measurement_time(Duration::from_secs(10));
-    group.sample_size(200);
-
-    use fast_qr::datamasking::Mask;
-
-    let mut mat = black_box(QRCode::default(177));
-    for (mask, id) in [
-        (Mask::Checkerboard, "checkerboard"),
-        (Mask::HorizontalLines, "horizontal_lines"),
-        (Mask::VerticalLines, "vertical_lines"),
-        (Mask::DiagonalLines, "diagonal_lines"),
-        (Mask::LargeCheckerboard, "large_checkerboard"),
-        (Mask::Fields, "fields"),
-        (Mask::Diamonds, "diamonds"),
-        (Mask::Meadow, "meadow"),
-    ] {
-        group.bench_function(id, |b| {
-            b.iter(|| fast_qr::datamasking::mask(&mut mat, mask))
-        });
-    }
-
-    group.finish();
-}
-
 criterion_group!(benches, bench_fastqr_qrcode);
 criterion_main!(benches);
diff --git a/src/convert/image.rs b/src/convert/image.rs
index b4b953d..629d0f7 100644
--- a/src/convert/image.rs
+++ b/src/convert/image.rs
@@ -22,8 +22,7 @@
 //! # }
 //! ```
 
-use std::error::Error;
-use std::fmt::{Formatter, Write};
+use std::fmt::Formatter;
 use std::io;
 
 use crate::QRCode;
@@ -61,7 +60,7 @@ impl std::fmt::Display for ImageError {
         match self {
             ImageError::IoError(io_err) => f.write_str(io_err.to_string().as_str()),
             ImageError::ImageError(error) => f.write_str(error.as_str()),
-            ImageError::EncodingError(error) => f.write_str(error.as_str())
+            ImageError::EncodingError(error) => f.write_str(error.as_str()),
         }
     }
 }
diff --git a/src/version.rs b/src/version.rs
index 0784f06..b5c9ff3 100644
--- a/src/version.rs
+++ b/src/version.rs
@@ -630,6 +630,7 @@ impl Version {
     /// # Panics
     /// Function panics if `n` is not included in `(21..=177).step_by(4)`
     #[must_use]
+    #[cfg(any(test, feature = "svg", feature = "image", debug_assertions))]
     pub(crate) const fn from_n(n: usize) -> Self {
         use Version::{
             V01, V02, V03, V04, V05, V06, V07, V08, V09, V10, V11, V12, V13, V14, V15, V16, V17,