diff --git a/puer.c b/puer.c
index 4aee633..c204237 100644
--- a/puer.c
+++ b/puer.c
@@ -66,7 +66,7 @@ void xxtea128(uint32_t const key[4], uint32_t block[4]) {
 }
 
 uint32_t bytes2word(unsigned char const bytes[4]) {
-	return bytes[0] | bytes[1]<<8 | bytes[2]<<16 | bytes[3]<<24;
+	return (uint32_t)bytes[0] | (uint32_t)bytes[1]<<8 | (uint32_t)bytes[2]<<16 | (uint32_t)bytes[3]<<24;
 }
 
 void word2bytes(unsigned char *bytes, uint32_t word) {