diff --git a/LICENSE b/LICENSE
index 5863035..8af9075 100644
--- a/LICENSE
+++ b/LICENSE
@@ -12,6 +12,7 @@ Copyright 2018 Dominik Schmidt <domischmidt@swissonline.ch>
 Copyright 2018 Aaron Burrow <burrows@charstarstar.com>
 Copyright 2020 Nihal Jere <nihal@nihaljere.xyz>
 Copyright 2020 Rainer Holzner <rholzner@web.de>
+Copyright 2020 Jeremy Bobbin <jer@jer.cx>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted, provided that the above
diff --git a/http.c b/http.c
index 249c168..8cf0ee4 100644
--- a/http.c
+++ b/http.c
@@ -531,7 +531,7 @@ http_send_response(int fd, struct request *r)
 		}
 
 		/* compare with last modification date of the file */
-		if (difftime(st.st_mtim.tv_sec, mktime(&tm)) <= 0) {
+		if (difftime(st.st_mtim.tv_sec, timegm(&tm)) <= 0) {
 			if (dprintf(fd,
 			            "HTTP/1.1 %d %s\r\n"
 			            "Date: %s\r\n"