diff --git a/mshow.c b/mshow.c
index f3b73a8..1c496fb 100644
--- a/mshow.c
+++ b/mshow.c
@@ -84,7 +84,7 @@ print_u8recode(char *body, size_t bodylen, char *srcenc)
 
 	ic = iconv_open("UTF-8", srcenc);
 	if (ic == (iconv_t)-1) {
-		printf("unsupported encoding: %s\n", srcenc);
+		fprintf(stderr, "unsupported encoding: %s\n", srcenc);
 		return;
 	}