X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/e94dde391b011f1cbfc2a6b8d08ad2a07121a31f..be3ed0da8343bdbd68665bef9a9bb096865bea04:/charset/mimeenc.c

diff --git a/charset/mimeenc.c b/charset/mimeenc.c
index 437781f6..93ad89e7 100644
--- a/charset/mimeenc.c
+++ b/charset/mimeenc.c
@@ -202,7 +202,7 @@ int charset_from_mimeenc(const char *name)
 	p = name;
 	q = mimeencs[i].name;
 	while (*p || *q) {
-	    if (tolower(*p) != tolower(*q))
+		if (tolower((unsigned char)*p) != tolower((unsigned char)*q))
 		break;
 	    p++; q++;
 	}