Add additional #include directives to avoid implicit function
declarations and build failures with future compilers.

diff --git a/lib/long-options.c b/lib/long-options.c
index 76b979634aa4be46..9ee8f6609cdd2c2b 100644
--- a/lib/long-options.c
+++ b/lib/long-options.c
@@ -22,6 +22,7 @@
 #endif
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <getopt.h>
 #include "long-options.h"
 
diff --git a/src/lsyslog.c b/src/lsyslog.c
index 6baf4a2b0a372fc5..0500280259b1af0a 100644
--- a/src/lsyslog.c
+++ b/src/lsyslog.c
@@ -18,11 +18,13 @@
   02111-1307, USA.
 
 */
+#define _GNU_SOURCE /* for vasprintf */
 #include "config.h"
 #ifdef ENABLE_SYSLOG
 #include "zglobal.h"
 #include <pwd.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #endif