diff --git a/src/dsp/dec_sse2.c b/src/dsp/dec_sse2.c
index cc640ea5..77c08c33 100644
--- a/src/dsp/dec_sse2.c
+++ b/src/dsp/dec_sse2.c
@@ -1062,7 +1062,7 @@ static void VE16_SSE2(uint8_t* dst) {
 static void HE16_SSE2(uint8_t* dst) {     // horizontal
   int j;
   for (j = 16; j > 0; --j) {
-    const __m128i values = _mm_set1_epi8(dst[-1]);
+    const __m128i values = _mm_set1_epi8((char)dst[-1]);
     _mm_storeu_si128((__m128i*)dst, values);
     dst += BPS;
   }
diff --git a/src/dsp/lossless_sse2.c b/src/dsp/lossless_sse2.c
index 4dd896ec..8c6a94f7 100644
--- a/src/dsp/lossless_sse2.c
+++ b/src/dsp/lossless_sse2.c
@@ -208,7 +208,7 @@ static void PredictorAdd0_SSE2(const uint32_t* in, const uint32_t* upper,
 static void PredictorAdd1_SSE2(const uint32_t* in, const uint32_t* upper,
                                int num_pixels, uint32_t* out) {
   int i;
-  __m128i prev = _mm_set1_epi32(out[-1]);
+  __m128i prev = _mm_set1_epi32((int)out[-1]);
   for (i = 0; i + 4 <= num_pixels; i += 4) {
     // a | b | c | d
     const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
@@ -561,7 +561,7 @@ static void ConvertBGRAToRGBA_SSE2(const uint32_t* src,
 static void ConvertBGRAToRGBA4444_SSE2(const uint32_t* src,
                                        int num_pixels, uint8_t* dst) {
   const __m128i mask_0x0f = _mm_set1_epi8(0x0f);
-  const __m128i mask_0xf0 = _mm_set1_epi8(0xf0);
+  const __m128i mask_0xf0 = _mm_set1_epi8((char)0xf0);
   const __m128i* in = (const __m128i*)src;
   __m128i* out = (__m128i*)dst;
   while (num_pixels >= 8) {
@@ -596,8 +596,8 @@ static void ConvertBGRAToRGBA4444_SSE2(const uint32_t* src,
 
 static void ConvertBGRAToRGB565_SSE2(const uint32_t* src,
                                      int num_pixels, uint8_t* dst) {
-  const __m128i mask_0xe0 = _mm_set1_epi8(0xe0);
-  const __m128i mask_0xf8 = _mm_set1_epi8(0xf8);
+  const __m128i mask_0xe0 = _mm_set1_epi8((char)0xe0);
+  const __m128i mask_0xf8 = _mm_set1_epi8((char)0xf8);
   const __m128i mask_0x07 = _mm_set1_epi8(0x07);
   const __m128i* in = (const __m128i*)src;
   __m128i* out = (__m128i*)dst;
diff --git a/src/dsp/lossless_sse41.c b/src/dsp/lossless_sse41.c
index ed41a4b0..bb7ce761 100644
--- a/src/dsp/lossless_sse41.c
+++ b/src/dsp/lossless_sse41.c
@@ -25,8 +25,9 @@ static void TransformColorInverse_SSE41(const VP8LMultipliers* const m,
                                         int num_pixels, uint32_t* dst) {
 // sign-extended multiplying constants, pre-shifted by 5.
 #define CST(X)  (((int16_t)(m->X << 8)) >> 5)   // sign-extend
-  const __m128i mults_rb = _mm_set1_epi32((uint32_t)CST(green_to_red_) << 16 |
-                                          (CST(green_to_blue_) & 0xffff));
+  const __m128i mults_rb =
+      _mm_set1_epi32((int)((uint32_t)CST(green_to_red_) << 16 |
+                           (CST(green_to_blue_) & 0xffff)));
   const __m128i mults_b2 = _mm_set1_epi32(CST(red_to_blue_));
 #undef CST
   const __m128i mask_ag = _mm_set1_epi32((int)0xff00ff00);