diff --git a/src/enc/analysis.c b/src/enc/analysis.c
index ce6338b7..4d7ce8ae 100644
--- a/src/enc/analysis.c
+++ b/src/enc/analysis.c
@@ -253,7 +253,7 @@ static int MBAnalyzeBestIntra16Mode(VP8EncIterator* const it) {
 
 static int MBAnalyzeBestIntra4Mode(VP8EncIterator* const it,
                                    int best_alpha) {
-  int modes[16];
+  uint8_t modes[16];
   const int max_mode = (it->enc_->method_ >= 3) ? MAX_INTRA4_MODE : NUM_BMODES;
   int i4_alpha = 0;
   VP8IteratorStartI4(it);
diff --git a/src/enc/iterator.c b/src/enc/iterator.c
index ea0222fc..16dbe0c1 100644
--- a/src/enc/iterator.c
+++ b/src/enc/iterator.c
@@ -294,15 +294,13 @@ void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode) {
   it->mb_->type_ = 1;
 }
 
-void VP8SetIntra4Mode(const VP8EncIterator* const it, int modes[16]) {
+void VP8SetIntra4Mode(const VP8EncIterator* const it, const uint8_t* modes) {
   uint8_t* preds = it->preds_;
   int y;
-  for (y = 0; y < 4; ++y) {
-    int x;
-    for (x = 0; x < 4; ++x) {
-      preds[x] = modes[x + y * 4];
-    }
+  for (y = 4; y > 0; --y) {
+    memcpy(preds, modes, 4 * sizeof(*modes));
     preds += it->enc_->preds_w_;
+    modes += 4;
   }
   it->mb_->type_ = 0;
 }
diff --git a/src/enc/quant.c b/src/enc/quant.c
index 3dc1042b..ea153849 100644
--- a/src/enc/quant.c
+++ b/src/enc/quant.c
@@ -742,7 +742,7 @@ static void PickBestIntra16(VP8EncIterator* const it, VP8ModeScore* const rd) {
 
 // return the cost array corresponding to the surrounding prediction modes.
 static const uint16_t* GetCostModeI4(VP8EncIterator* const it,
-                                     const int modes[16]) {
+                                     const uint8_t modes[16]) {
   const int preds_w = it->enc_->preds_w_;
   const int x = (it->i4_ & 3), y = it->i4_ >> 2;
   const int left = (x == 0) ? it->preds_[y * preds_w - 1] : modes[it->i4_ - 1];
diff --git a/src/enc/vp8enci.h b/src/enc/vp8enci.h
index 35295eee..326f7b19 100644
--- a/src/enc/vp8enci.h
+++ b/src/enc/vp8enci.h
@@ -243,7 +243,7 @@ typedef struct {
   int16_t y_ac_levels[16][16];
   int16_t uv_levels[4 + 4][16];
   int mode_i16;               // mode number for intra16 prediction
-  int modes_i4[16];           // mode numbers for intra4 predictions
+  uint8_t modes_i4[16];       // mode numbers for intra4 predictions
   int mode_uv;                // mode number of chroma prediction
   uint32_t nz;                // non-zero blocks
 } VP8ModeScore;
@@ -306,7 +306,7 @@ void VP8IteratorBytesToNz(VP8EncIterator* const it);
 
 // Helper functions to set mode properties
 void VP8SetIntra16Mode(const VP8EncIterator* const it, int mode);
-void VP8SetIntra4Mode(const VP8EncIterator* const it, int modes[16]);
+void VP8SetIntra4Mode(const VP8EncIterator* const it, const uint8_t* modes);
 void VP8SetIntraUVMode(const VP8EncIterator* const it, int mode);
 void VP8SetSkip(const VP8EncIterator* const it, int skip);
 void VP8SetSegment(const VP8EncIterator* const it, int segment);