diff --git a/libswscale/swscale.c b/libswscale/swscale.c
index 577a0dfa9de473418150865e062ec62301ab0384..2cac8729e24f572ed39823fd8eba3ebe12c44e96 100644
--- a/libswscale/swscale.c
+++ b/libswscale/swscale.c
@@ -264,12 +264,12 @@ static unsigned char clip_table[768];
 
 static SwsVector *sws_getConvVec(SwsVector *a, SwsVector *b);
 
-const uint8_t  __attribute__((aligned(8))) dither_2x2_4[2][8]={
+static const uint8_t  __attribute__((aligned(8))) dither_2x2_4[2][8]={
 {  1,   3,   1,   3,   1,   3,   1,   3, },
 {  2,   0,   2,   0,   2,   0,   2,   0, },
 };
 
-const uint8_t  __attribute__((aligned(8))) dither_2x2_8[2][8]={
+static const uint8_t  __attribute__((aligned(8))) dither_2x2_8[2][8]={
 {  6,   2,   6,   2,   6,   2,   6,   2, },
 {  0,   4,   0,   4,   0,   4,   0,   4, },
 };
diff --git a/libswscale/yuv2rgb.c b/libswscale/yuv2rgb.c
index 9b64c06dec10b1a6ed9b53d9a5402c4c042e590f..d19430fd17d67a9953d23bc5e947e22aefb6f242 100644
--- a/libswscale/yuv2rgb.c
+++ b/libswscale/yuv2rgb.c
@@ -41,8 +41,6 @@
 
 #define DITHER1XBPP // only for MMX
 
-extern const uint8_t dither_2x2_4[2][8];
-extern const uint8_t dither_2x2_8[2][8];
 extern const uint8_t dither_8x8_32[8][8];
 extern const uint8_t dither_8x8_73[8][8];
 extern const uint8_t dither_8x8_220[8][8];