diff --git a/src/utils/utils.h b/src/utils/utils.h
index c7620f91..2a3ec926 100644
--- a/src/utils/utils.h
+++ b/src/utils/utils.h
@@ -92,14 +92,14 @@ static WEBP_INLINE uint32_t GetLE32(const uint8_t* const data) {
 // Store 16, 24 or 32 bits in little-endian order.
 static WEBP_INLINE void PutLE16(uint8_t* const data, int val) {
   assert(val < (1 << 16));
-  data[0] = (val >> 0);
-  data[1] = (val >> 8);
+  data[0] = (val >> 0) & 0xff;
+  data[1] = (val >> 8) & 0xff;
 }
 
 static WEBP_INLINE void PutLE24(uint8_t* const data, int val) {
   assert(val < (1 << 24));
   PutLE16(data, val & 0xffff);
-  data[2] = (val >> 16);
+  data[2] = (val >> 16) & 0xff;
 }
 
 static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) {