diff --git a/src/dsp/alpha_processing_sse2.c b/src/dsp/alpha_processing_sse2.c
index a5f8c9f7..f0843d0f 100644
--- a/src/dsp/alpha_processing_sse2.c
+++ b/src/dsp/alpha_processing_sse2.c
@@ -26,8 +26,8 @@ static int DispatchAlpha_SSE2(const uint8_t* WEBP_RESTRICT alpha,
   uint32_t alpha_and = 0xff;
   int i, j;
   const __m128i zero = _mm_setzero_si128();
-  const __m128i rgb_mask = _mm_set1_epi32(0xffffff00u);  // to preserve RGB
-  const __m128i all_0xff = _mm_set_epi32(0, 0, ~0u, ~0u);
+  const __m128i rgb_mask = _mm_set1_epi32((int)0xffffff00);  // to preserve RGB
+  const __m128i all_0xff = _mm_set_epi32(0, 0, ~0, ~0);
   __m128i all_alphas = all_0xff;
 
   // We must be able to access 3 extra bytes after the last written byte
@@ -106,8 +106,8 @@ static int ExtractAlpha_SSE2(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
   // value is not 0xff if any of the alpha[] is not equal to 0xff.
   uint32_t alpha_and = 0xff;
   int i, j;
-  const __m128i a_mask = _mm_set1_epi32(0xffu);  // to preserve alpha
-  const __m128i all_0xff = _mm_set_epi32(0, 0, ~0u, ~0u);
+  const __m128i a_mask = _mm_set1_epi32(0xff);  // to preserve alpha
+  const __m128i all_0xff = _mm_set_epi32(0, 0, ~0, ~0);
   __m128i all_alphas = all_0xff;
 
   // We must be able to access 3 extra bytes after the last written byte
@@ -178,7 +178,7 @@ static int ExtractAlpha_SSE2(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
 static void ApplyAlphaMultiply_SSE2(uint8_t* rgba, int alpha_first,
                                     int w, int h, int stride) {
   const __m128i zero = _mm_setzero_si128();
-  const __m128i kMult = _mm_set1_epi16(0x8081u);
+  const __m128i kMult = _mm_set1_epi16((short)0x8081);
   const __m128i kMask = _mm_set_epi16(0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0);
   const int kSpan = 4;
   while (h-- > 0) {
@@ -267,7 +267,7 @@ static int HasAlpha32b_SSE2(const uint8_t* src, int length) {
 }
 
 static void AlphaReplace_SSE2(uint32_t* src, int length, uint32_t color) {
-  const __m128i m_color = _mm_set1_epi32(color);
+  const __m128i m_color = _mm_set1_epi32((int)color);
   const __m128i zero = _mm_setzero_si128();
   int i = 0;
   for (; i + 8 <= length; i += 8) {
diff --git a/src/dsp/alpha_processing_sse41.c b/src/dsp/alpha_processing_sse41.c
index cdf877ce..1156ac34 100644
--- a/src/dsp/alpha_processing_sse41.c
+++ b/src/dsp/alpha_processing_sse41.c
@@ -26,7 +26,7 @@ static int ExtractAlpha_SSE41(const uint8_t* WEBP_RESTRICT argb,
   // value is not 0xff if any of the alpha[] is not equal to 0xff.
   uint32_t alpha_and = 0xff;
   int i, j;
-  const __m128i all_0xff = _mm_set1_epi32(~0u);
+  const __m128i all_0xff = _mm_set1_epi32(~0);
   __m128i all_alphas = all_0xff;
 
   // We must be able to access 3 extra bytes after the last written byte
diff --git a/src/dsp/dec_sse2.c b/src/dsp/dec_sse2.c
index 8964b527..cc640ea5 100644
--- a/src/dsp/dec_sse2.c
+++ b/src/dsp/dec_sse2.c
@@ -1070,7 +1070,7 @@ static void HE16_SSE2(uint8_t* dst) {     // horizontal
 
 static WEBP_INLINE void Put16_SSE2(uint8_t v, uint8_t* dst) {
   int j;
-  const __m128i values = _mm_set1_epi8(v);
+  const __m128i values = _mm_set1_epi8((char)v);
   for (j = 0; j < 16; ++j) {
     _mm_storeu_si128((__m128i*)(dst + j * BPS), values);
   }
@@ -1130,7 +1130,7 @@ static void VE8uv_SSE2(uint8_t* dst) {    // vertical
 // helper for chroma-DC predictions
 static WEBP_INLINE void Put8x8uv_SSE2(uint8_t v, uint8_t* dst) {
   int j;
-  const __m128i values = _mm_set1_epi8(v);
+  const __m128i values = _mm_set1_epi8((char)v);
   for (j = 0; j < 8; ++j) {
     _mm_storel_epi64((__m128i*)(dst + j * BPS), values);
   }
diff --git a/src/dsp/enc_sse2.c b/src/dsp/enc_sse2.c
index 600a019b..e39ea52d 100644
--- a/src/dsp/enc_sse2.c
+++ b/src/dsp/enc_sse2.c
@@ -481,7 +481,7 @@ static void CollectHistogram_SSE2(const uint8_t* ref, const uint8_t* pred,
 // helper for chroma-DC predictions
 static WEBP_INLINE void Put8x8uv_SSE2(uint8_t v, uint8_t* dst) {
   int j;
-  const __m128i values = _mm_set1_epi8(v);
+  const __m128i values = _mm_set1_epi8((char)v);
   for (j = 0; j < 8; ++j) {
     _mm_storel_epi64((__m128i*)(dst + j * BPS), values);
   }
@@ -489,7 +489,7 @@ static WEBP_INLINE void Put8x8uv_SSE2(uint8_t v, uint8_t* dst) {
 
 static WEBP_INLINE void Put16_SSE2(uint8_t v, uint8_t* dst) {
   int j;
-  const __m128i values = _mm_set1_epi8(v);
+  const __m128i values = _mm_set1_epi8((char)v);
   for (j = 0; j < 16; ++j) {
     _mm_store_si128((__m128i*)(dst + j * BPS), values);
   }
@@ -540,7 +540,7 @@ static WEBP_INLINE void VerticalPred_SSE2(uint8_t* dst,
 static WEBP_INLINE void HE8uv_SSE2(uint8_t* dst, const uint8_t* left) {
   int j;
   for (j = 0; j < 8; ++j) {
-    const __m128i values = _mm_set1_epi8(left[j]);
+    const __m128i values = _mm_set1_epi8((char)left[j]);
     _mm_storel_epi64((__m128i*)dst, values);
     dst += BPS;
   }
@@ -549,7 +549,7 @@ static WEBP_INLINE void HE8uv_SSE2(uint8_t* dst, const uint8_t* left) {
 static WEBP_INLINE void HE16_SSE2(uint8_t* dst, const uint8_t* left) {
   int j;
   for (j = 0; j < 16; ++j) {
-    const __m128i values = _mm_set1_epi8(left[j]);
+    const __m128i values = _mm_set1_epi8((char)left[j]);
     _mm_store_si128((__m128i*)dst, values);
     dst += BPS;
   }
diff --git a/src/dsp/lossless_enc_sse2.c b/src/dsp/lossless_enc_sse2.c
index 948001a3..66cbaab7 100644
--- a/src/dsp/lossless_enc_sse2.c
+++ b/src/dsp/lossless_enc_sse2.c
@@ -54,8 +54,8 @@ static void TransformColor_SSE2(const VP8LMultipliers* const m,
   const __m128i mults_rb = MK_CST_16(CST_5b(m->green_to_red_),
                                      CST_5b(m->green_to_blue_));
   const __m128i mults_b2 = MK_CST_16(CST_5b(m->red_to_blue_), 0);
-  const __m128i mask_ag = _mm_set1_epi32(0xff00ff00);  // alpha-green masks
-  const __m128i mask_rb = _mm_set1_epi32(0x00ff00ff);  // red-blue masks
+  const __m128i mask_ag = _mm_set1_epi32((int)0xff00ff00);  // alpha-green masks
+  const __m128i mask_rb = _mm_set1_epi32(0x00ff00ff);       // red-blue masks
   int i;
   for (i = 0; i + 4 <= num_pixels; i += 4) {
     const __m128i in = _mm_loadu_si128((__m128i*)&argb_data[i]); // argb
@@ -376,7 +376,7 @@ static void BundleColorMap_SSE2(const uint8_t* const row, int width, int xbits,
       break;
     }
     case 2: {
-      const __m128i mask_or = _mm_set1_epi32(0xff000000);
+      const __m128i mask_or = _mm_set1_epi32((int)0xff000000);
       const __m128i mul_cst = _mm_set1_epi16(0x0104);
       const __m128i mask_mul = _mm_set1_epi16(0x0f00);
       for (x = 0; x + 16 <= width; x += 16, dst += 4) {
@@ -427,7 +427,7 @@ static WEBP_INLINE void Average2_m128i(const __m128i* const a0,
 static void PredictorSub0_SSE2(const uint32_t* in, const uint32_t* upper,
                                int num_pixels, uint32_t* out) {
   int i;
-  const __m128i black = _mm_set1_epi32(ARGB_BLACK);
+  const __m128i black = _mm_set1_epi32((int)ARGB_BLACK);
   for (i = 0; i + 4 <= num_pixels; i += 4) {
     const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
     const __m128i res = _mm_sub_epi8(src, black);
diff --git a/src/dsp/lossless_sse2.c b/src/dsp/lossless_sse2.c
index 396cb0bd..4dd896ec 100644
--- a/src/dsp/lossless_sse2.c
+++ b/src/dsp/lossless_sse2.c
@@ -192,7 +192,7 @@ static uint32_t Predictor13_SSE2(const uint32_t* const left,
 static void PredictorAdd0_SSE2(const uint32_t* in, const uint32_t* upper,
                                int num_pixels, uint32_t* out) {
   int i;
-  const __m128i black = _mm_set1_epi32(ARGB_BLACK);
+  const __m128i black = _mm_set1_epi32((int)ARGB_BLACK);
   for (i = 0; i + 4 <= num_pixels; i += 4) {
     const __m128i src = _mm_loadu_si128((const __m128i*)&in[i]);
     const __m128i res = _mm_add_epi8(src, black);
@@ -468,7 +468,7 @@ static void TransformColorInverse_SSE2(const VP8LMultipliers* const m,
   const __m128i mults_b2 = MK_CST_16(CST(red_to_blue_), 0);
 #undef MK_CST_16
 #undef CST
-  const __m128i mask_ag = _mm_set1_epi32(0xff00ff00);  // alpha-green masks
+  const __m128i mask_ag = _mm_set1_epi32((int)0xff00ff00);  // alpha-green masks
   int i;
   for (i = 0; i + 4 <= num_pixels; i += 4) {
     const __m128i in = _mm_loadu_si128((const __m128i*)&src[i]); // argb
@@ -532,7 +532,7 @@ static void ConvertBGRAToRGB_SSE2(const uint32_t* src, int num_pixels,
 
 static void ConvertBGRAToRGBA_SSE2(const uint32_t* src,
                                    int num_pixels, uint8_t* dst) {
-  const __m128i red_blue_mask = _mm_set1_epi32(0x00ff00ffu);
+  const __m128i red_blue_mask = _mm_set1_epi32(0x00ff00ff);
   const __m128i* in = (const __m128i*)src;
   __m128i* out = (__m128i*)dst;
   while (num_pixels >= 8) {
diff --git a/src/dsp/lossless_sse41.c b/src/dsp/lossless_sse41.c
index b0d6daa7..ed41a4b0 100644
--- a/src/dsp/lossless_sse41.c
+++ b/src/dsp/lossless_sse41.c
@@ -29,7 +29,7 @@ static void TransformColorInverse_SSE41(const VP8LMultipliers* const m,
                                           (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(0xff00ff00);
+  const __m128i mask_ag = _mm_set1_epi32((int)0xff00ff00);
   const __m128i perm1 = _mm_setr_epi8(-1, 1, -1, 1, -1, 5, -1, 5,
                                       -1, 9, -1, 9, -1, 13, -1, 13);
   const __m128i perm2 = _mm_setr_epi8(-1, 2, -1, -1, -1, 6, -1, -1,
diff --git a/src/dsp/rescaler_sse2.c b/src/dsp/rescaler_sse2.c
index bcd765dc..3f18e94e 100644
--- a/src/dsp/rescaler_sse2.c
+++ b/src/dsp/rescaler_sse2.c
@@ -198,7 +198,7 @@ static WEBP_INLINE void ProcessRow_SSE2(const __m128i* const A0,
                                         const __m128i* const mult,
                                         uint8_t* const dst) {
   const __m128i rounder = _mm_set_epi32(0, ROUNDER, 0, ROUNDER);
-  const __m128i mask = _mm_set_epi32(0xffffffffu, 0, 0xffffffffu, 0);
+  const __m128i mask = _mm_set_epi32(~0, 0, ~0, 0);
   const __m128i B0 = _mm_mul_epu32(*A0, *mult);
   const __m128i B1 = _mm_mul_epu32(*A1, *mult);
   const __m128i B2 = _mm_mul_epu32(*A2, *mult);
diff --git a/src/dsp/yuv_sse2.c b/src/dsp/yuv_sse2.c
index 970bbb78..cae435b8 100644
--- a/src/dsp/yuv_sse2.c
+++ b/src/dsp/yuv_sse2.c
@@ -130,7 +130,7 @@ static WEBP_INLINE void PackAndStore4444_SSE2(const __m128i* const R,
   const __m128i rg0 = _mm_packus_epi16(*B, *A);
   const __m128i ba0 = _mm_packus_epi16(*R, *G);
 #endif
-  const __m128i mask_0xf0 = _mm_set1_epi8(0xf0);
+  const __m128i mask_0xf0 = _mm_set1_epi8((char)0xf0);
   const __m128i rb1 = _mm_unpacklo_epi8(rg0, ba0);  // rbrbrbrbrb...
   const __m128i ga1 = _mm_unpackhi_epi8(rg0, ba0);  // gagagagaga...
   const __m128i rb2 = _mm_and_si128(rb1, mask_0xf0);
@@ -147,9 +147,10 @@ static WEBP_INLINE void PackAndStore565_SSE2(const __m128i* const R,
   const __m128i r0 = _mm_packus_epi16(*R, *R);
   const __m128i g0 = _mm_packus_epi16(*G, *G);
   const __m128i b0 = _mm_packus_epi16(*B, *B);
-  const __m128i r1 = _mm_and_si128(r0, _mm_set1_epi8(0xf8));
+  const __m128i r1 = _mm_and_si128(r0, _mm_set1_epi8((char)0xf8));
   const __m128i b1 = _mm_and_si128(_mm_srli_epi16(b0, 3), _mm_set1_epi8(0x1f));
-  const __m128i g1 = _mm_srli_epi16(_mm_and_si128(g0, _mm_set1_epi8(0xe0)), 5);
+  const __m128i g1 =
+      _mm_srli_epi16(_mm_and_si128(g0, _mm_set1_epi8((char)0xe0)), 5);
   const __m128i g2 = _mm_slli_epi16(_mm_and_si128(g0, _mm_set1_epi8(0x1c)), 3);
   const __m128i rg = _mm_or_si128(r1, g1);
   const __m128i gb = _mm_or_si128(g2, b1);