--- a/pcap_ex.c
+++ b/pcap_ex.c
@@ -11,6 +11,7 @@
 # include <string.h>
 # include <signal.h>
 # include <unistd.h>
+# include <stdlib.h>
 #endif
 
 #include <pcap.h>
@@ -300,7 +300,7 @@
 	char ebuf[PCAP_ERRBUF_SIZE];
 	int ret = -1;
 
-	mktemp(path);
+	mkstemp(path);
 	if ((f = fopen(path, "w")) != NULL) {
 		hdr.magic = 0xa1b2c3d4;
 		hdr.version_major = PCAP_VERSION_MAJOR;