diff --git a/src/fserve.c b/src/fserve.c
index ef40af75..80720283 100644
--- a/src/fserve.c
+++ b/src/fserve.c
@@ -432,20 +432,25 @@ int fserve_client_create(client_t *httpclient, char *path)
                 time_t now;
                 int strflen;
                 time(&now);
+                struct tm result;
+                int64_t endpos = rangenumber+new_content_len-1;
+                if (endpos < 0) {
+                    endpos = 0;
+                }
                 strflen = strftime(currenttime, 50, "%a, %d-%b-%Y %X GMT",
-                                   gmtime(&now));
+                                   gmtime_r(&now, &result));
                 httpclient->respcode = 206;
                 bytes = sock_write(httpclient->con->sock,
                     "HTTP/1.1 206 Partial Content\r\n"
                     "Date: %s\r\n"
-                    "Content-Length: %ld\r\n"
+                    "Content-Length: " FORMAT_INT64 "\r\n"
                     "Content-Range: bytes " FORMAT_INT64 \
                     "-" FORMAT_INT64 "/" FORMAT_INT64 "\r\n"
                     "Content-Type: %s\r\n\r\n",
                     currenttime,
                     new_content_len,
                     rangenumber,
-                    client->content_length-1,
+                    endpos,
                     client->content_length,
                     fserve_content_type(path));
                 if(bytes > 0) httpclient->con->sent_bytes = bytes;