diff --git a/fs/smb/client/compress/lz77.c b/fs/smb/client/compress/lz77.c
index 96e8a8057a77..cdd6b53766b0 100644
--- a/fs/smb/client/compress/lz77.c
+++ b/fs/smb/client/compress/lz77.c
@@ -221,7 +221,7 @@ noinline int lz77_compress(const void *src, u32 slen, void *dst, u32 *dlen)
 	}
 
 	flag <<= (32 - flag_count);
-	flag |= (1 << (32 - flag_count)) - 1;
+	flag |= (1UL << (32 - flag_count)) - 1;
 	lz77_write32(flag_pos, flag);
 
 	*dlen = dstp - dst;