diff --git a/libavutil/bswap.h b/libavutil/bswap.h
index c93825f6ee10e72b0a45cc37cfbae5bf9b2d95e9..3657ccd402c345bdcbbf407ccda42d5951ff5fad 100644
--- a/libavutil/bswap.h
+++ b/libavutil/bswap.h
@@ -74,11 +74,6 @@ static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
 #ifndef av_bswap64
 static inline uint64_t av_const av_bswap64(uint64_t x)
 {
-#if 0
-    x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
-    x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
-    return (x>>32) | (x<<32);
-#else
     union {
         uint64_t ll;
         uint32_t l[2];
@@ -87,7 +82,6 @@ static inline uint64_t av_const av_bswap64(uint64_t x)
     r.l[0] = av_bswap32 (w.l[1]);
     r.l[1] = av_bswap32 (w.l[0]);
     return r.ll;
-#endif
 }
 #endif