diff --git a/src/mame/machine/naomibd.c b/src/mame/machine/naomibd.c
index 3bcfb211638..e641cf2c642 100644
--- a/src/mame/machine/naomibd.c
+++ b/src/mame/machine/naomibd.c
@@ -516,14 +516,14 @@ static void naomibd_m1_decode(naomibd_state *naomibd)
 
 // Streaming M2/M3 protection and decompression
 
-INLINE UINT16 bswap16(UINT16 in)
+INLINE UINT16 naomi_bswap16(UINT16 in)
 {
     return ((in>>8) | (in<<8));
 }
 
 static UINT16 naomibd_get_decrypted_stream(naomibd_state *naomibd)
 {
-	UINT16 wordn = bswap16(naomibd->prot.ptr[naomibd->prot.count++]);
+	UINT16 wordn = naomi_bswap16(naomibd->prot.ptr[naomibd->prot.count++]);
 
 	naomibd->prot.aux_word = block_decrypt(naomibd->dc_gamekey, naomibd->dc_seqkey, naomibd->prot.seed++, wordn);
 	wordn = (naomibd->prot.last_word&~3) | (naomibd->prot.aux_word&3);