diff --git a/src/Sprites.cpp b/src/Sprites.cpp
index 8b81ce3..d6860e7 100644
--- a/src/Sprites.cpp
+++ b/src/Sprites.cpp
@@ -148,10 +148,11 @@ void Sprites::drawBitmap(int16_t x, int16_t y,
             Arduboy2Base::sBuffer[ofs] = data;
           }
           if (yOffset != 0 && sRow < 7) {
-            data = Arduboy2Base::sBuffer[ofs + WIDTH];
-            data &= (*((unsigned char *) (&mask_data) + 1));
-            data |= (*((unsigned char *) (&bitmap_data) + 1));
-            Arduboy2Base::sBuffer[ofs + WIDTH] = data;
+            const size_t index = static_cast<uint16_t>(ofs + WIDTH);
+            data = Arduboy2Base::sBuffer[index];
+            data &= (uint8_t)(mask_data >> 8);
+            data |= (uint8_t)(bitmap_data >> 8);
+            Arduboy2Base::sBuffer[index] = data;
           }
           ofs++;
           bofs++;
@@ -170,7 +171,8 @@ void Sprites::drawBitmap(int16_t x, int16_t y,
             Arduboy2Base::sBuffer[ofs] |= (uint8_t)(bitmap_data);
           }
           if (yOffset != 0 && sRow < 7) {
-            Arduboy2Base::sBuffer[ofs + WIDTH] |= (*((unsigned char *) (&bitmap_data) + 1));
+            const size_t index = static_cast<uint16_t>(ofs + WIDTH);
+            Arduboy2Base::sBuffer[index] |= (uint8_t)(bitmap_data >> 8);
           }
           ofs++;
           bofs++;
@@ -189,7 +191,8 @@ void Sprites::drawBitmap(int16_t x, int16_t y,
             Arduboy2Base::sBuffer[ofs]  &= ~(uint8_t)(bitmap_data);
           }
           if (yOffset != 0 && sRow < 7) {
-            Arduboy2Base::sBuffer[ofs + WIDTH] &= ~(*((unsigned char *) (&bitmap_data) + 1));
+            const size_t index = static_cast<uint16_t>(ofs + WIDTH);
+            Arduboy2Base::sBuffer[index] &= ~(uint8_t)(bitmap_data >> 8);
           }
           ofs++;
           bofs++;
@@ -223,10 +226,11 @@ void Sprites::drawBitmap(int16_t x, int16_t y,
             Arduboy2Base::sBuffer[ofs] = data;
           }
           if (yOffset != 0 && sRow < 7) {
-            data = Arduboy2Base::sBuffer[ofs + WIDTH];
-            data &= (*((unsigned char *) (&mask_data) + 1));
-            data |= (*((unsigned char *) (&bitmap_data) + 1));
-            Arduboy2Base::sBuffer[ofs + WIDTH] = data;
+            const size_t index = static_cast<uint16_t>(ofs + WIDTH);
+            data = Arduboy2Base::sBuffer[index];
+            data &= (uint8_t)(mask_data >> 8);
+            data |= (uint8_t)(bitmap_data >> 8);
+            Arduboy2Base::sBuffer[index] = data;
           }
           ofs++;
           mask_ofs++;
diff --git a/src/SpritesB.cpp b/src/SpritesB.cpp
index 27924ae..5f7c1b9 100644
--- a/src/SpritesB.cpp
+++ b/src/SpritesB.cpp
@@ -159,10 +159,11 @@ void SpritesB::drawBitmap(int16_t x, int16_t y,
         Arduboy2Base::sBuffer[ofs] = data;
       }
       if (yOffset != 0 && sRow < 7) {
-        data = Arduboy2Base::sBuffer[ofs + WIDTH];
-        data &= (*((unsigned char *) (&mask_data) + 1));
-        data |= (*((unsigned char *) (&bitmap_data) + 1));
-        Arduboy2Base::sBuffer[ofs + WIDTH] = data;
+        const size_t index = static_cast<uint16_t>(ofs + WIDTH);
+        data = Arduboy2Base::sBuffer[index];
+        data &= (uint8_t)(mask_data >> 8);
+        data |= (uint8_t)(bitmap_data >> 8);
+        Arduboy2Base::sBuffer[index] = data;
       }
       ofs++;
       mask_ofs += ofs_step;