diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 56657a42c4..a1e12a8aaa 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -174,7 +174,7 @@ reached_end_position(XLogRecPtr segendpos, uint32 timeline,
 						lo;
 
 			MemSet(xlogend, 0, sizeof(xlogend));
-			r = read(bgpipe[0], xlogend, sizeof(xlogend));
+			r = read(bgpipe[0], xlogend, sizeof(xlogend)-1);
 			if (r < 0)
 			{
 				fprintf(stderr, _("%s: could not read from ready pipe: %s\n"),