--- a/tap.c
+++ b/tap.c
@@ -94,7 +94,7 @@
 	else
 		n = strtoul(argv[1],NULL,0);
 
-	if (!(n)&&(argv[1] != '\0')) {
+	if (!(n)&&(*argv[1] != '\0')) {
 		fprintf (stderr, "%s: Unreadable integer arg.; Assuming 1.\n",argv[0]);
 		n = 1;
 	}
--- a/tpipe.c
+++ b/tpipe.c
@@ -41,6 +41,7 @@
 
 #include <stdio.h>
 #include <string.h>	/* strcmp() */
+#include <stdlib.h>
 
 #ifndef VERSION
 #define VERSION "1.6"