diff --git a/libavcodec/bitstream.h b/libavcodec/bitstream.h
index a00e117689..26b4f8d8c0 100644
--- a/libavcodec/bitstream.h
+++ b/libavcodec/bitstream.h
@@ -200,7 +200,7 @@ unaligned(16)
 unaligned(32)
 unaligned(64)
 #undef unaligned
-#endif //!ARCH_X86
+#endif /* defined(ARCH_X86) || defined(ARCH_X86_64) */
 
 #ifndef ALT_BITSTREAM_WRITER
 static inline void put_bits(PutBitContext *s, int n, unsigned int value)
diff --git a/libpostproc/postprocess.c b/libpostproc/postprocess.c
index 559bc81ab9..a81cf20db1 100644
--- a/libpostproc/postprocess.c
+++ b/libpostproc/postprocess.c
@@ -594,7 +594,7 @@ static always_inline void do_a_deblock_C(uint8_t *src, int step, int stride, PPC
 #if (defined (HAVE_3DNOW) && !defined (HAVE_MMX2)) || defined (RUNTIME_CPUDETECT)
 #define COMPILE_3DNOW
 #endif
-#endif //ARCH_X86
+#endif /* defined(ARCH_X86) || defined(ARCH_X86_64) */
 
 #undef HAVE_MMX
 #undef HAVE_MMX2