diff --git a/libavcodec/lossless_videoencdsp.c b/libavcodec/lossless_videoencdsp.c
index e2dc99e201..8d03a5b5c6 100644
--- a/libavcodec/lossless_videoencdsp.c
+++ b/libavcodec/lossless_videoencdsp.c
@@ -18,19 +18,31 @@
 
 #include "config.h"
 #include "libavutil/attributes.h"
+#include "libavutil/intreadwrite.h"
 #include "lossless_videoencdsp.h"
 #include "mathops.h"
 
+#if HAVE_FAST_64BIT
+typedef uint64_t uint_native;
+#define READ   AV_RN64
+#define READA  AV_RN64A
+#define WRITEA AV_WN64A
+#else
+typedef uint32_t uint_native;
+#define READ   AV_RN32
+#define READA  AV_RN32A
+#define WRITEA AV_WN32A
+#endif
 // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
-#define pb_7f (~0UL / 255 * 0x7f)
-#define pb_80 (~0UL / 255 * 0x80)
+#define pb_7f (~(uint_native)0 / 255 * 0x7f)
+#define pb_80 (~(uint_native)0 / 255 * 0x80)
 
 static void diff_bytes_c(uint8_t *dst, const uint8_t *src1, const uint8_t *src2, intptr_t w)
 {
     long i;
 
 #if !HAVE_FAST_UNALIGNED
-    if (((long)src1 | (long)src2) & (sizeof(long) - 1)) {
+    if (((uintptr_t)src1 | (uintptr_t)src2) & (sizeof(uint_native) - 1)) {
         for (i = 0; i + 7 < w; i += 8) {
             dst[i + 0] = src1[i + 0] - src2[i + 0];
             dst[i + 1] = src1[i + 1] - src2[i + 1];
@@ -43,11 +55,10 @@ static void diff_bytes_c(uint8_t *dst, const uint8_t *src1, const uint8_t *src2,
         }
     } else
 #endif
-    for (i = 0; i <= w - (int) sizeof(long); i += sizeof(long)) {
-        long a = *(long *) (src1 + i);
-        long b = *(long *) (src2 + i);
-        *(long *) (dst + i) = ((a | pb_80) - (b & pb_7f)) ^
-                              ((a ^ b ^ pb_80) & pb_80);
+    for (i = 0; i <= w - (int) sizeof(uint_native); i += sizeof(uint_native)) {
+        uint_native a = READA(src1 + i);
+        uint_native b = READ(src2 + i);
+        WRITEA(dst + i, ((a | pb_80) - (b & pb_7f)) ^ ((a ^ b ^ pb_80) & pb_80));
     }
     for (; i < w; i++)
         dst[i + 0] = src1[i + 0] - src2[i + 0];