diff --git a/src/implementation/algorithm.rs b/src/implementation/algorithm.rs
index 3ec1c82c..cced2472 100644
--- a/src/implementation/algorithm.rs
+++ b/src/implementation/algorithm.rs
@@ -181,21 +181,19 @@ macro_rules! algorithm_simd {
 
             #[cfg_attr(not(target_arch="aarch64"), target_feature(enable = $feat))]
             #[inline]
-            #[allow(unconditional_panic)] // does not panic because len is checked
-            #[allow(const_err)] // the same, but for Rust 1.38.0
             unsafe fn check_block(&mut self, input: SimdInput) {
                 // WORKAROUND
                 // necessary because the for loop is not unrolled on ARM64
                 if input.vals.len() == 2 {
-                    self.check_bytes(input.vals[0]);
-                    self.check_bytes(input.vals[1]);
-                    self.incomplete = Self::is_incomplete(input.vals[1]);
+                    self.check_bytes(*input.vals.get_unchecked(0));
+                    self.check_bytes(*input.vals.get_unchecked(1));
+                    self.incomplete = Self::is_incomplete(*input.vals.get_unchecked(1));
                 } else if input.vals.len() == 4 {
-                    self.check_bytes(input.vals[0]);
-                    self.check_bytes(input.vals[1]);
-                    self.check_bytes(input.vals[2]);
-                    self.check_bytes(input.vals[3]);
-                    self.incomplete = Self::is_incomplete(input.vals[3]);
+                    self.check_bytes(*input.vals.get_unchecked(0));
+                    self.check_bytes(*input.vals.get_unchecked(1));
+                    self.check_bytes(*input.vals.get_unchecked(2));
+                    self.check_bytes(*input.vals.get_unchecked(3));
+                    self.incomplete = Self::is_incomplete(*input.vals.get_unchecked(3));
                 } else {
                     panic!("Unsupported number of chunks");
                 }
diff --git a/src/implementation/helpers.rs b/src/implementation/helpers.rs
index f3efe189..37b21a8a 100644
--- a/src/implementation/helpers.rs
+++ b/src/implementation/helpers.rs
@@ -30,7 +30,6 @@ pub(crate) fn get_compat_error(input: &[u8], failing_block_pos: usize) -> Utf8Er
         // UTF-8 codepoint, is thus complete and valid UTF-8. We start the check with the
         // current block in that case.
         (1..=3)
-            .into_iter()
             .find(|i| input[failing_block_pos - i] >> 6 != 0b10)
             .map_or(failing_block_pos, |i| failing_block_pos - i)
     };