diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6c05e38..75b3cfd 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,6 +30,12 @@ jobs:
             feature: simd128
         rust: [nightly, stable, 1.64]
         exclude:
+          # https://github.com/rust-lang/rust/issues/131031
+          - target:
+              triple: wasm32-wasip1
+              feature: simd128
+            rust: nightly
+          # In 1.64 it's still called wasm32-wasi
           - target:
               triple: wasm32-wasip1
               feature: simd128
diff --git a/src/arch/aarch64.rs b/src/arch/aarch64.rs
index fcfb939..52dd045 100644
--- a/src/arch/aarch64.rs
+++ b/src/arch/aarch64.rs
@@ -59,24 +59,17 @@ pub(crate) fn check(input: &[u8]) -> bool {
 
 #[target_feature(enable = "neon")]
 pub(crate) unsafe fn check_neon(input: &[u8]) -> bool {
-    let ascii_zero = vdupq_n_u8(b'0' - 1);
-    let ascii_nine = vdupq_n_u8(b'9' + 1);
-    let ascii_ua = vdupq_n_u8(b'A' - 1);
-    let ascii_uf = vdupq_n_u8(b'F' + 1);
-    let ascii_la = vdupq_n_u8(b'a' - 1);
-    let ascii_lf = vdupq_n_u8(b'f' + 1);
-
     generic::check_unaligned_chunks(input, |chunk: uint8x16_t| {
-        let ge0 = vcgtq_u8(chunk, ascii_zero);
-        let le9 = vcltq_u8(chunk, ascii_nine);
+        let ge0 = vcgeq_u8(chunk, vdupq_n_u8(b'0'));
+        let le9 = vcleq_u8(chunk, vdupq_n_u8(b'9'));
         let valid_digit = vandq_u8(ge0, le9);
 
-        let geua = vcgtq_u8(chunk, ascii_ua);
-        let leuf = vcltq_u8(chunk, ascii_uf);
+        let geua = vcgeq_u8(chunk, vdupq_n_u8(b'A'));
+        let leuf = vcleq_u8(chunk, vdupq_n_u8(b'F'));
         let valid_upper = vandq_u8(geua, leuf);
 
-        let gela = vcgtq_u8(chunk, ascii_la);
-        let lelf = vcltq_u8(chunk, ascii_lf);
+        let gela = vcgeq_u8(chunk, vdupq_n_u8(b'a'));
+        let lelf = vcleq_u8(chunk, vdupq_n_u8(b'f'));
         let valid_lower = vandq_u8(gela, lelf);
 
         let valid_letter = vorrq_u8(valid_lower, valid_upper);
diff --git a/src/arch/wasm32.rs b/src/arch/wasm32.rs
index 381ea96..f13f751 100644
--- a/src/arch/wasm32.rs
+++ b/src/arch/wasm32.rs
@@ -65,11 +65,11 @@ pub(crate) fn check(input: &[u8]) -> bool {
     if !has_simd128() {
         return generic::check(input);
     }
-    unsafe { check_simd128(input) }
+    check_simd128(input)
 }
 
 #[target_feature(enable = "simd128")]
-unsafe fn check_simd128(input: &[u8]) -> bool {
+fn check_simd128(input: &[u8]) -> bool {
     generic::check_unaligned_chunks(input, |chunk: v128| {
         let ge0 = u8x16_ge(chunk, u8x16_splat(b'0'));
         let le9 = u8x16_le(chunk, u8x16_splat(b'9'));