diff --git a/libavcodec/x86/mpegvideo_mmx.c b/libavcodec/x86/mpegvideo_mmx.c
index c84fb0114f..a32e35b6b7 100644
--- a/libavcodec/x86/mpegvideo_mmx.c
+++ b/libavcodec/x86/mpegvideo_mmx.c
@@ -581,6 +581,8 @@ static void  denoise_dct_sse2(MpegEncContext *s, DCTELEM *block){
             " jb 1b                             \n\t"
         : "+r" (block), "+r" (sum), "+r" (offset)
         : "r"(block+64)
+          XMM_CLOBBERS_ONLY("%xmm0", "%xmm1", "%xmm2", "%xmm3",
+                            "%xmm4", "%xmm5", "%xmm6", "%xmm7")
     );
 }
 
diff --git a/libavcodec/x86/mpegvideo_mmx_template.c b/libavcodec/x86/mpegvideo_mmx_template.c
index 0d927921e2..b292c9d170 100644
--- a/libavcodec/x86/mpegvideo_mmx_template.c
+++ b/libavcodec/x86/mpegvideo_mmx_template.c
@@ -180,6 +180,8 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
             : "+a" (last_non_zero_p1)
             : "r" (block+64), "r" (qmat), "r" (bias),
               "r" (inv_zigzag_direct16+64), "r" (temp_block+64)
+              XMM_CLOBBERS_ONLY("%xmm0", "%xmm1", "%xmm2", "%xmm3",
+                                "%xmm4", "%xmm5", "%xmm6", "%xmm7")
         );
     }else{ // FMT_H263
         __asm__ volatile(
@@ -212,6 +214,8 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
             : "+a" (last_non_zero_p1)
             : "r" (block+64), "r" (qmat+64), "r" (bias+64),
               "r" (inv_zigzag_direct16+64), "r" (temp_block+64)
+              XMM_CLOBBERS_ONLY("%xmm0", "%xmm1", "%xmm2", "%xmm3",
+                                "%xmm4", "%xmm5", "%xmm6", "%xmm7")
         );
     }
     __asm__ volatile(