diff --git a/src/avx2/fdct.rs b/src/avx2/fdct.rs
index b7caa38..ec12b72 100644
--- a/src/avx2/fdct.rs
+++ b/src/avx2/fdct.rs
@@ -64,10 +64,11 @@ pub fn fdct_avx2(data: &mut [i16; 64]) {
 }
 
 #[target_feature(enable = "avx2")]
-unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
+fn fdct_avx2_internal(data: &mut [i16; 64]) {
+    #[target_feature(enable = "avx2")]
     #[allow(non_snake_case)]
-    #[inline(always)]
-    unsafe fn PW_F130_F054_MF130_F054() -> __m256i {
+    #[inline]
+    fn PW_F130_F054_MF130_F054() -> __m256i {
         _mm256_set_epi16(
             F_0_541,
             F_0_541 - F_1_847,
@@ -88,9 +89,10 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
         )
     }
 
+    #[target_feature(enable = "avx2")]
     #[allow(non_snake_case)]
-    #[inline(always)]
-    unsafe fn PW_MF078_F117_F078_F117() -> __m256i {
+    #[inline]
+    fn PW_MF078_F117_F078_F117() -> __m256i {
         _mm256_set_epi16(
             F_1_175,
             F_1_175 - F_0_390,
@@ -111,9 +113,10 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
         )
     }
 
+    #[target_feature(enable = "avx2")]
     #[allow(non_snake_case)]
-    #[inline(always)]
-    unsafe fn PW_MF060_MF089_MF050_MF256() -> __m256i {
+    #[inline]
+    fn PW_MF060_MF089_MF050_MF256() -> __m256i {
         _mm256_set_epi16(
             -F_2_562,
             F_2_053 - F_2_562,
@@ -134,9 +137,10 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
         )
     }
 
+    #[target_feature(enable = "avx2")]
     #[allow(non_snake_case)]
-    #[inline(always)]
-    unsafe fn PW_F050_MF256_F060_MF089() -> __m256i {
+    #[inline]
+    fn PW_F050_MF256_F060_MF089() -> __m256i {
         _mm256_set_epi16(
             -F_0_899,
             F_1_501 - F_0_899,
@@ -157,9 +161,10 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
         )
     }
 
+    #[target_feature(enable = "avx2")]
     #[allow(non_snake_case)]
-    #[inline(always)]
-    unsafe fn PD_DESCALE_P(first_pass: bool) -> __m256i {
+    #[inline]
+    fn PD_DESCALE_P(first_pass: bool) -> __m256i {
         if first_pass {
             _mm256_set_epi32(
                 1 << (DESCALE_P1 - 1),
@@ -185,9 +190,10 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
         }
     }
 
+    #[target_feature(enable = "avx2")]
     #[allow(non_snake_case)]
-    #[inline(always)]
-    unsafe fn PW_DESCALE_P2X() -> __m256i {
+    #[inline]
+    fn PW_DESCALE_P2X() -> __m256i {
         _mm256_set_epi32(
             1 << (PASS1_BITS - 1),
             1 << (PASS1_BITS - 1),
@@ -201,8 +207,9 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
     }
 
     // In-place 8x8x16-bit matrix transpose using AVX2 instructions
-    #[inline(always)]
-    unsafe fn do_transpose(
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    fn do_transpose(
         i1: __m256i,
         i2: __m256i,
         i3: __m256i,
@@ -244,8 +251,9 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
     }
 
     // In-place 8x8x16-bit accurate integer forward DCT using AVX2 instructions
-    #[inline(always)]
-    unsafe fn do_dct(
+    #[target_feature(enable = "avx2")]
+    #[inline]
+    fn do_dct(
         first_pass: bool,
         i1: __m256i,
         i2: __m256i,
@@ -412,12 +420,10 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
         (t1, t2, t3, t4)
     }
 
-    let in_data = core::mem::transmute::<*mut i16, *mut __m256i>(data.as_mut_ptr());
-
-    let ymm4 = _mm256_loadu_si256(in_data);
-    let ymm5 = _mm256_loadu_si256(in_data.add(1));
-    let ymm6 = _mm256_loadu_si256(in_data.add(2));
-    let ymm7 = _mm256_loadu_si256(in_data.add(3));
+    let ymm4 = avx_load(&data[0..16]);
+    let ymm5 = avx_load(&data[16..32]);
+    let ymm6 = avx_load(&data[32..48]);
+    let ymm7 = avx_load(&data[48..64]);
 
     // ---- Pass 1: process rows.
     // ymm4=(00 01 02 03 04 05 06 07  10 11 12 13 14 15 16 17)
@@ -451,10 +457,28 @@ unsafe fn fdct_avx2_internal(data: &mut [i16; 64]) {
     let ymm6 = _mm256_permute2x128_si256(ymm0, ymm4, 0x31); // ymm6=data4_5
     let ymm7 = _mm256_permute2x128_si256(ymm2, ymm4, 0x21); // ymm7=data6_7
 
-    let out_data = core::mem::transmute::<*mut i16, *mut __m256i>(data.as_mut_ptr());
+    avx_store(ymm3, &mut data[0..16]);
+    avx_store(ymm5, &mut data[16..32]);
+    avx_store(ymm6, &mut data[32..48]);
+    avx_store(ymm7, &mut data[48..64]);
+}
 
-    _mm256_storeu_si256(out_data, ymm3);
-    _mm256_storeu_si256(out_data.add(1), ymm5);
-    _mm256_storeu_si256(out_data.add(2), ymm6);
-    _mm256_storeu_si256(out_data.add(3), ymm7);
+/// Safe wrapper for an unaligned AVX load
+#[target_feature(enable = "avx2")]
+#[inline]
+fn avx_load(input: &[i16]) -> __m256i {
+    assert!(input.len() == 16);
+    assert!(core::mem::size_of::<[i16; 16]>() == core::mem::size_of::<__m256i>());
+    // SAFETY: we've checked sizes above. The load is unaligned, so no alignment requirements.
+    unsafe { _mm256_loadu_si256(input.as_ptr() as *const __m256i) }
 }
+
+/// Safe wrapper for an unaligned AVX store
+#[target_feature(enable = "avx2")]
+#[inline]
+fn avx_store(input: __m256i, output: &mut [i16]) {
+    assert!(output.len() == 16);
+    assert!(core::mem::size_of::<[i16; 16]>() == core::mem::size_of::<__m256i>());
+    // SAFETY: we've checked sizes above. The load is unaligned, so no alignment requirements.
+    unsafe { _mm256_storeu_si256(output.as_mut_ptr() as *mut __m256i, input) }
+}
\ No newline at end of file