diff --git a/src/apcupsd.c b/src/apcupsd.c
index c7a40c9c..95065e29 100644
--- a/src/apcupsd.c
+++ b/src/apcupsd.c
@@ -104,7 +104,7 @@ static int get_line(int sock, char line[], short linesize) {
 	while (sz > linesize) {
 		// this is just a hack (being lazy), this should not happen anyway
 		net_recv(sock, line, linesize);
-		sz -= sizeof(line);
+		sz -= linesize;
 	}
 	if (!net_recv(sock, line, sz)) return 0;
 	line[sz] = 0;